automatic language selection did not work on windows 7 hungarian

I made hungarian translations to gnumed, and wanted to check it under windows, so i made hu and hu_HU directories under C:\Program Files (x86)\GNUmed-client\po\ and copied the 'compiled' gnumed.mo file to LC_MESSAGES directory, but the login screen language didn't changed.

I inspected the debug log, and found out, that the 'guessed' language is not 'hu' nor 'hu_HU' but 'Hungarian_Hungary'.
So I made a copy of the hu folder to Hungarian_Hungary but it didn't bring any changes. Interface remained english.

I looked the python source and found out that the gettext external 'module/routine' does the actual .mo file search and usage.
Because I can not debug it, I started to search for windows language errors, and find the --lang-gettext parameter. Using it I was able to set the language to 'de' (what comes preinstalled) and 'hu' too.

Although I have a workaround, it would be nice if automatic detection (and probably loading of .mo files) would work too.

A slightly edited logfile (only removed date+time and virtual file path of python files):
CRITICAL gm.logging (gmlog2::__setup_logging() #269): -------- start of logging ------------------------------
INFO gm.logging (gmlog2::__setup_logging() #270): log file is <C:\Users\atus\.gnumed-logs\gnumed\gnumed-2015_05_13-09_43_18-2128.log>
INFO gm.logging (gmlog2::__setup_logging() #271): log level is [DEBUG]
INFO gm.logging (gmlog2::__setup_logging() #272): log file encoding is <utf8>
INFO gm.logging (gmlog2::__setup_logging() #273): initial python.str -> python.unicode encoding is <cp1250>
INFO gm.launcher (<string>::log_startup_info() #277): GNUmed client version [1.5.4] on branch [1.5]
INFO gm.launcher (<string>::log_startup_info() #278): Platform: ('Windows', 'atus-fujitsu', '7', '6.1.7601', 'x86', 'Intel64 Family 6 Model 37 Stepping 5, GenuineIntel')
INFO gm.launcher (<string>::log_startup_info() #279): Python 2.6.6 (r266:84297, Aug 24 2010, 18:46:32) [MSC v.1500 32 bit (Intel)] on win32 (nt)
INFO gm.launcher (<string>::log_startup_info() #285): process environment:
INFO gm.launcher (<string>::log_startup_info() #289): ${TMP}: C:\Users\atus\AppData\Local\Temp
INFO gm.launcher (<string>::log_startup_info() #289): ${COMPUTERNAME}: ATUS-FUJITSU
INFO gm.launcher (<string>::log_startup_info() #289): ${USERDOMAIN}: atus-fujitsu
INFO gm.launcher (<string>::log_startup_info() #289): ${PSMODULEPATH}: C:\Windows\system32\WindowsPowerShell\v1.0\Modules\
INFO gm.launcher (<string>::log_startup_info() #289): ${COMMONPROGRAMFILES}: C:\Program Files (x86)\Common Files
INFO gm.launcher (<string>::log_startup_info() #289): ${PROCESSOR_IDENTIFIER}: Intel64 Family 6 Model 37 Stepping 5, GenuineIntel
INFO gm.launcher (<string>::log_startup_info() #289): ${PROGRAMFILES}: C:\Program Files (x86)
INFO gm.launcher (<string>::log_startup_info() #289): ${PROCESSOR_REVISION}: 2505
INFO gm.launcher (<string>::log_startup_info() #289): ${SYSTEMROOT}: C:\Windows
INFO gm.launcher (<string>::log_startup_info() #289): ${PATH}: C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\WinSCP\;C:\Program Files (x86)\Skype\Phone\;C:\Program Files (x86)\OpenVPN\bin;C:\Program Files (x86)\IDM Computer Solutions\UltraEdit\
INFO gm.launcher (<string>::log_startup_info() #289): ${PROGRAMFILES(X86)}: C:\Program Files (x86)
INFO gm.launcher (<string>::log_startup_info() #289): ${COMSPEC}: C:\Windows\system32\cmd.exe
INFO gm.launcher (<string>::log_startup_info() #289): ${TEMP}: C:\Users\atus\AppData\Local\Temp
INFO gm.launcher (<string>::log_startup_info() #289): ${COMMONPROGRAMFILES(X86)}: C:\Program Files (x86)\Common Files
INFO gm.launcher (<string>::log_startup_info() #289): ${PROCESSOR_ARCHITECTURE}: x86
INFO gm.launcher (<string>::log_startup_info() #289): ${ALLUSERSPROFILE}: C:\ProgramData
INFO gm.launcher (<string>::log_startup_info() #289): ${LOCALAPPDATA}: C:\Users\atus\AppData\Local
INFO gm.launcher (<string>::log_startup_info() #289): ${HOMEPATH}: \Users\atus
INFO gm.launcher (<string>::log_startup_info() #289): ${PROGRAMW6432}: C:\Program Files
INFO gm.launcher (<string>::log_startup_info() #289): ${USERNAME}: atus
INFO gm.launcher (<string>::log_startup_info() #289): ${LOGONSERVER}: \\ATUS-FUJITSU
INFO gm.launcher (<string>::log_startup_info() #289): ${SESSIONNAME}: Console
INFO gm.launcher (<string>::log_startup_info() #289): ${PROGRAMDATA}: C:\ProgramData
INFO gm.launcher (<string>::log_startup_info() #289): ${PATHEXT}: .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC
INFO gm.launcher (<string>::log_startup_info() #289): ${FP_NO_HOST_CHECK}: NO
INFO gm.launcher (<string>::log_startup_info() #289): ${WINDIR}: C:\Windows
INFO gm.launcher (<string>::log_startup_info() #289): ${APPDATA}: C:\Users\atus\AppData\Roaming
INFO gm.launcher (<string>::log_startup_info() #289): ${HOMEDRIVE}: C:
INFO gm.launcher (<string>::log_startup_info() #289): ${SYSTEMDRIVE}: C:
INFO gm.launcher (<string>::log_startup_info() #289): ${NUMBER_OF_PROCESSORS}: 2
INFO gm.launcher (<string>::log_startup_info() #289): ${VBOX_INSTALL_PATH}: C:\Program Files\Oracle\VirtualBox\
INFO gm.launcher (<string>::log_startup_info() #289): ${PROCESSOR_LEVEL}: 6
INFO gm.launcher (<string>::log_startup_info() #289): ${PROCESSOR_ARCHITEW6432}: AMD64
INFO gm.launcher (<string>::log_startup_info() #289): ${COMMONPROGRAMW6432}: C:\Program Files\Common Files
INFO gm.launcher (<string>::log_startup_info() #289): ${OS}: Windows_NT
INFO gm.launcher (<string>::log_startup_info() #289): ${PUBLIC}: C:\Users\Public
INFO gm.launcher (<string>::log_startup_info() #289): ${USERPROFILE}: C:\Users\atus
INFO gm.cfg (gmcfg2::add_cli() #507): adding command line arguments
DEBUG gm.cfg (gmcfg2::add_cli() #508): raw command line is:
DEBUG gm.cfg (gmcfg2::add_cli() #509): ['C:\\Program Files (x86)\\GNUmed-client\\bin\\gnumed.exe', '--lang-gettext=de']
DEBUG gm.cfg (gmcfg2::get() #389): option [--debug] not in group [cli] in source [cli]
DEBUG gm.cfg (gmcfg2::get() #389): option [--slave] not in group [cli] in source [cli]
DEBUG gm.cfg (gmcfg2::get() #389): option [--skip-update-check] not in group [cli] in source [cli]
DEBUG gm.cfg (gmcfg2::get() #389): option [--hipaa] not in group [cli] in source [cli]
DEBUG gm.cfg (gmcfg2::get() #389): option [--local-import] not in group [cli] in source [cli]
DEBUG gm.launcher (<string>::setup_local_repo_path() #204): [C:\Users\atus\.gnumed\local_code\1.5\Gnumed\wxGladeWidgets] not found
INFO gm.launcher (<string>::setup_local_repo_path() #205): local wxGlade widgets repository not available
INFO gm.datetime (gmdatetime::<module>() #59): mx.DateTime version: 3.2.1
DEBUG gm.hook (gmhooks::<module>() #69): known hooks:
DEBUG gm.hook (gmhooks::<module>() #71): post_patient_activation
DEBUG gm.hook (gmhooks::<module>() #71): post_person_creation
DEBUG gm.hook (gmhooks::<module>() #71): shutdown-post-GUI
DEBUG gm.hook (gmhooks::<module>() #71): startup-after-GUI-init
DEBUG gm.hook (gmhooks::<module>() #71): startup-before-GUI
DEBUG gm.hook (gmhooks::<module>() #71): request_user_attention
DEBUG gm.hook (gmhooks::<module>() #71): app_activated_startup
DEBUG gm.hook (gmhooks::<module>() #71): app_activated
DEBUG gm.hook (gmhooks::<module>() #71): app_deactivated
DEBUG gm.hook (gmhooks::<module>() #71): after_substance_intake_modified
DEBUG gm.hook (gmhooks::<module>() #71): after_test_result_modified
DEBUG gm.hook (gmhooks::<module>() #71): after_soap_modified
DEBUG gm.hook (gmhooks::<module>() #71): after_code_link_modified
DEBUG gm.hook (gmhooks::<module>() #71): after_new_doc_created
DEBUG gm.hook (gmhooks::<module>() #71): before_print_doc
DEBUG gm.hook (gmhooks::<module>() #71): before_fax_doc
DEBUG gm.hook (gmhooks::<module>() #71): before_mail_doc
DEBUG gm.hook (gmhooks::<module>() #71): before_print_doc_part
DEBUG gm.hook (gmhooks::<module>() #71): before_fax_doc_part
DEBUG gm.hook (gmhooks::<module>() #71): before_mail_doc_part
DEBUG gm.hook (gmhooks::<module>() #71): before_external_doc_access
DEBUG gm.hook (gmhooks::<module>() #71): db_maintenance_warning
WARNING gm.i18n (gmi18n::__log_locale_settings() #112): this OS does not have locale.LC_MESSAGES
DEBUG gm.i18n (gmi18n::__log_locale_settings() #122): unmodified startup locale settings (should be [C])
DEBUG gm.i18n (gmi18n::__log_locale_settings() #124): current locale settings:
DEBUG gm.i18n (gmi18n::__log_locale_settings() #125): locale.get_locale(): (None, None)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #127): locale.get_locale(LC_MONETARY): (None, None)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #127): locale.get_locale(LC_TIME): (None, None)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #127): locale.get_locale(LC_COLLATE): (None, None)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #127): locale.get_locale(LC_CTYPE): (None, None)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #127): locale.get_locale(LC_NUMERIC): (None, None)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #130): (locale.set_locale(LC_NUMERIC): C)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #130): (locale.set_locale(LC_MONETARY): C)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #130): (locale.set_locale(LC_COLLATE): C)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #130): (locale.set_locale(LC_CTYPE): C)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #130): (locale.set_locale(LC_ALL): C)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #130): (locale.set_locale(LC_TIME): C)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #133): locale.getdefaultlocale() - default (user) locale: ('hu_HU', 'cp1250')
DEBUG gm.i18n (gmi18n::__log_locale_settings() #137): encoding sanity check (also check "locale.nl_langinfo(CODESET)" below):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #142): sys.getdefaultencoding(): [ascii]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #143): locale.getpreferredencoding(): [cp1250]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #144): locale.getlocale()[1]: [None]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #145): sys.getfilesystemencoding(): [mbcs]
WARNING gm.i18n (gmi18n::__log_locale_settings() #152): encoding suggested by locale (cp1250) does not match encoding currently set in locale (None)
WARNING gm.i18n (gmi18n::__log_locale_settings() #153): this might lead to encoding errors
DEBUG gm.i18n (gmi18n::__log_locale_settings() #158): <codecs> module CAN handle encoding [cp1250]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #158): <codecs> module CAN handle encoding [ascii]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #158): <codecs> module CAN handle encoding [mbcs]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #161): on Linux you can determine a likely candidate for the encoding by running "locale charmap"
DEBUG gm.i18n (gmi18n::__log_locale_settings() #163): locale related environment variables (${LANG} is typically used):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #168): ${LANGUAGE} not set
DEBUG gm.i18n (gmi18n::__log_locale_settings() #168): ${LC_ALL} not set
DEBUG gm.i18n (gmi18n::__log_locale_settings() #168): ${LC_CTYPE} not set
DEBUG gm.i18n (gmi18n::__log_locale_settings() #168): ${LANG} not set
DEBUG gm.i18n (gmi18n::__log_locale_settings() #170): database of locale conventions:
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(mon_decimal_point):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(int_frac_digits): 127
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(p_sep_by_space): 127
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(frac_digits): 127
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(thousands_sep):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(n_sign_posn): 127
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(decimal_point): .
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(int_curr_symbol):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(n_cs_precedes): 127
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(p_sign_posn): 127
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(mon_thousands_sep):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(negative_sign):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(currency_symbol):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(n_sep_by_space): 127
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(mon_grouping): []
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(p_cs_precedes): 127
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(positive_sign):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #174): locale.localeconv(grouping): []
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.CODESET
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.D_T_FMT
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.D_FMT
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.T_FMT
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.T_FMT_AMPM
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.RADIXCHAR
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.THOUSEP
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.YESEXPR
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.NOEXPR
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.CRNCYSTR
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.ERA
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.ERA_D_T_FMT
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.ERA_D_FMT
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.ALT_DIGITS
DEBUG gm.i18n (gmi18n::get_encoding() #418): *actual* encoding of locale is None, using encoding *recommended* by locale
DEBUG gm.i18n (gmi18n::__log_locale_settings() #198): gmI18N.get_encoding(): cp1250
DEBUG gm.i18n (gmi18n::activate_locale() #249): activating user-default locale with <locale.setlocale(locale.LC_ALL, '')> returns: [Hungarian_Hungary.1250]
WARNING gm.i18n (gmi18n::__log_locale_settings() #112): this OS does not have locale.LC_MESSAGES
DEBUG gm.i18n (gmi18n::__log_locale_settings() #122): locale settings after activating user-default locale
DEBUG gm.i18n (gmi18n::__log_locale_settings() #124): current locale settings:
DEBUG gm.i18n (gmi18n::__log_locale_settings() #125): locale.get_locale(): ('Hungarian_Hungary', '1250')
DEBUG gm.i18n (gmi18n::__log_locale_settings() #127): locale.get_locale(LC_MONETARY): ('Hungarian_Hungary', '1250')
DEBUG gm.i18n (gmi18n::__log_locale_settings() #127): locale.get_locale(LC_TIME): ('Hungarian_Hungary', '1250')
DEBUG gm.i18n (gmi18n::__log_locale_settings() #127): locale.get_locale(LC_COLLATE): ('Hungarian_Hungary', '1250')
DEBUG gm.i18n (gmi18n::__log_locale_settings() #127): locale.get_locale(LC_CTYPE): ('Hungarian_Hungary', '1250')
DEBUG gm.i18n (gmi18n::__log_locale_settings() #127): locale.get_locale(LC_NUMERIC): ('Hungarian_Hungary', '1250')
DEBUG gm.i18n (gmi18n::__log_locale_settings() #130): (locale.set_locale(LC_NUMERIC): Hungarian_Hungary.1250)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #130): (locale.set_locale(LC_MONETARY): Hungarian_Hungary.1250)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #130): (locale.set_locale(LC_COLLATE): Hungarian_Hungary.1250)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #130): (locale.set_locale(LC_CTYPE): Hungarian_Hungary.1250)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #130): (locale.set_locale(LC_ALL): Hungarian_Hungary.1250)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #130): (locale.set_locale(LC_TIME): Hungarian_Hungary.1250)
DEBUG gm.i18n (gmi18n::__log_locale_settings() #133): locale.getdefaultlocale() - default (user) locale: ('hu_HU', 'cp1250')
DEBUG gm.i18n (gmi18n::__log_locale_settings() #137): encoding sanity check (also check "locale.nl_langinfo(CODESET)" below):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #142): sys.getdefaultencoding(): [ascii]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #143): locale.getpreferredencoding(): [cp1250]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #144): locale.getlocale()[1]: [1250]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #145): sys.getfilesystemencoding(): [mbcs]
WARNING gm.i18n (gmi18n::__log_locale_settings() #152): encoding suggested by locale (cp1250) does not match encoding currently set in locale (1250)
WARNING gm.i18n (gmi18n::__log_locale_settings() #153): this might lead to encoding errors
DEBUG gm.i18n (gmi18n::__log_locale_settings() #158): <codecs> module CAN handle encoding [cp1250]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #158): <codecs> module CAN handle encoding [1250]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #158): <codecs> module CAN handle encoding [ascii]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #158): <codecs> module CAN handle encoding [mbcs]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #161): on Linux you can determine a likely candidate for the encoding by running "locale charmap"
DEBUG gm.i18n (gmi18n::__log_locale_settings() #163): locale related environment variables (${LANG} is typically used):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #168): ${LANGUAGE} not set
DEBUG gm.i18n (gmi18n::__log_locale_settings() #168): ${LC_ALL} not set
DEBUG gm.i18n (gmi18n::__log_locale_settings() #168): ${LC_CTYPE} not set
DEBUG gm.i18n (gmi18n::__log_locale_settings() #168): ${LANG} not set
DEBUG gm.i18n (gmi18n::__log_locale_settings() #170): database of locale conventions:
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(mon_decimal_point): ,
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(int_frac_digits): 2
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(p_sep_by_space): 1
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(frac_digits): 2
DEBUG gm.i18n (gmi18n::__log_locale_settings() #179): locale.localeconv(thousands_sep):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(n_sign_posn): 1
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(decimal_point): ,
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(int_curr_symbol): HUF
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(n_cs_precedes): 0
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(p_sign_posn): 1
DEBUG gm.i18n (gmi18n::__log_locale_settings() #179): locale.localeconv(mon_thousands_sep):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(negative_sign): -
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(currency_symbol): Ft
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(n_sep_by_space): 1
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(mon_grouping): [3, 0]
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(p_cs_precedes): 0
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(positive_sign):
DEBUG gm.i18n (gmi18n::__log_locale_settings() #177): locale.localeconv(grouping): [3, 0]
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.CODESET
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.D_T_FMT
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.D_FMT
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.T_FMT
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.T_FMT_AMPM
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.RADIXCHAR
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.THOUSEP
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.YESEXPR
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.NOEXPR
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.CRNCYSTR
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.ERA
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.ERA_D_T_FMT
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.ERA_D_FMT
WARNING gm.i18n (gmi18n::__log_locale_settings() #185): this OS does not support nl_langinfo category locale.ALT_DIGITS
DEBUG gm.i18n (gmi18n::__log_locale_settings() #198): gmI18N.get_encoding(): 1250
DEBUG gm.i18n (gmi18n::__split_locale_into_levels() #95): splitting canonical locale [Hungarian_Hungary] into levels
DEBUG gm.i18n (gmi18n::__split_locale_into_levels() #104): system locale levels: {'country': 'Hungarian_Hungary', 'full': 'Hungarian_Hungary', 'language': 'Hungarian'}
DEBUG gm.cfg (gmcfg2::get() #389): option [--text-domain] not in group [cli] in source [cli]
DEBUG gm.cfg (gmcfg2::get() #391): option [cli::--lang-gettext] found in source [cli]
DEBUG gm.cfg (gmcfg2::get() #391): option [internal::local-import] found in source [internal]
INFO gm.i18n (gmi18n::install_domain() #278): domain not specified, deriving from script name
INFO gm.i18n (gmi18n::install_domain() #281): text domain is [gnumed]
DEBUG gm.i18n (gmi18n::install_domain() #284): searching message catalog file for system locale [Hungarian_Hungary]
DEBUG gm.i18n (gmi18n::install_domain() #291): ${LANGUAGE} = [None]
DEBUG gm.i18n (gmi18n::install_domain() #291): ${LC_ALL} = [None]
DEBUG gm.i18n (gmi18n::install_domain() #291): ${LC_MESSAGES} = [None]
DEBUG gm.i18n (gmi18n::install_domain() #291): ${LANG} = [None]
INFO gm.i18n (gmi18n::install_domain() #294): explicit setting of ${LANG} requested: [de]
INFO gm.i18n (gmi18n::install_domain() #295): this will override the system locale language setting
DEBUG gm.i18n (gmi18n::install_domain() #323): No use looking in standard POSIX locations - not a POSIX system.
DEBUG gm.i18n (gmi18n::install_domain() #327): looking at ${GNUMED_DIR}
INFO gm.i18n (gmi18n::install_domain() #333): ${GNUMED_DIR} not set
DEBUG gm.i18n (gmi18n::install_domain() #342): looking above binary install directory [C:\Program Files (x86)\GNUmed-client\po]
DEBUG gm.i18n (gmi18n::install_domain() #346): looking in binary install directory [C:\Program Files (x86)\GNUmed-client\bin\po]
DEBUG gm.i18n (gmi18n::install_domain() #351): trying [C:\Program Files (x86)\GNUmed-client\po](/Hungarian_Hungary/LC_MESSAGES/gnumed.mo)
DEBUG gm.i18n (gmi18n::install_domain() #365): found msg catalog: [Translate this or i18n into <en_EN> will not work properly !] => [Übersetzen oder Bauchplatscher !]
INFO gm.logging (gmlog2::set_string_encoding() #233): setting python.str -> python.unicode encoding to <1250> (locale.getlocale)

it is interesting that in line 96, gnumed logs a getdefaultlocale result ('hu_HU', 'cp1250') what is not entirely used.
later at lines 147 and 148 the codepage part 'cp1250' is used to get a correspondig encoding (get_encoding) and this way it finds 'Hungarian_Hungary.1250'.

Despite the message in line 170: "explicit setting of ${LANG} requested: [de]" the log later in line 177 says it is trying [C:\Program Files (x86)\GNUmed-client\po](/Hungarian_Hungary/LC_MESSAGES/gnumed.mo) file, then the next line shows it found the requested deuch language.

On the other hand if I didn't set the --lang-gettext parameter, gnumed didn't find the hungarian (or any other language) in the mentioned file [C:\Program Files (x86)\GNUmed-client\po](/Hungarian_Hungary/LC_MESSAGES/gnumed.mo)

I inspected what happens with processmonitor, and found out that only the 'root' directory of language files were inspected:
14:58:00,0228186 gnumed.exe 3516 WriteFile C:\Users\atus\.gnumed-logs\gnumed\gnumed-2015_05_12-14_57_59-3516.log SUCCESS Offset: 44 462, Length: 247
14:58:00,0230173 gnumed.exe 3516 CreateFile C:\Program Files (x86)\GNUmed-client\po SUCCESS Desired Access: Read Attributes, Disposition: Open, Options: Open Reparse Point, Attributes: n/a, ShareMode: Read, Write, Delete, AllocationSize: n/a, OpenResult: Opened
14:58:00,0231254 gnumed.exe 3516 QueryNetworkOpenInformationFile C:\Program Files (x86)\GNUmed-client\po SUCCESS CreationTime: 2015.05.12. 12:32:10, LastAccessTime: 2015.05.12. 14:48:16, LastWriteTime: 2015.05.12. 14:48:16, ChangeTime: 2015.05.12. 14:48:16, AllocationSize: 1601.01.01. 2:00:00, EndOfFile: 1601.01.01. 2:00:00, FileAttributes: D
14:58:00,0231420 gnumed.exe 3516 CloseFile C:\Program Files (x86)\GNUmed-client\po SUCCESS
14:58:00,0233714 gnumed.exe 3516 WriteFile C:\Users\atus\.gnumed-logs\gnumed\gnumed-2015_05_12-14_57_59-3516.log SUCCESS Offset: 44 709, Length: 305

The correspondig log writes were:
2015-05-12 14:30:57 DEBUG gm.i18n (d:\workplace\gnumed-client.1.5.4\build\pyi.win32\gnumed\outpyz1.pyz\gnumed.pycommon.gmi18n::install_domain() #351): trying [C:\Program Files (x86)\GNUmed-client\po](/Hungarian_Hungary/LC_MESSAGES/gnumed.mo)
2015-05-12 14:30:57 DEBUG gm.i18n (d:\workplace\gnumed-client.1.5.4\build\pyi.win32\gnumed\outpyz1.pyz\gnumed.pycommon.gmi18n::install_domain() #362): does not translate: [Translate this or i18n into <en_EN> will not work properly !] => [Translate this or i18n into <en_EN> will not work properly !]