Unicode errors importing preferences

Whyteboard 0.41.1
Operating System: Linux 2.6.38-9-generic i686
Screen Resolution: 1440x900
Python Version: 2.7.1+ (r271:86832, Apr 11 2011, 18:05:24)
[GCC 4.5.2]
wxPython Version: 2.8.11.0 (gtk2-unicode)
wxPython Info: (__WXGTK__, wxGTK, unicode, gtk2, wx-assertions-off, SWIG-1.3.29)
Python Encoding: Default=ascii File=UTF-8
wxPython Encoding: utf-8
System Architecture: 32bit i686
Byte order: little
Frozen: False

#---- Preferences ----#
language = Greek

*** Mon May 30 19:30:59 2011 ***
Traceback (most recent call last):
  File \"/usr/share/whyteboard/whyteboard/gui/frame.py\", line 428, in on_import_pref
    os.rename(home, os.path.join(_dir, stamp + u\".user.pref\"))
UnicodeDecodeError: \'ascii\' codec can\'t decode byte 0xce in position 3: ordinal not in range(128)

*** Mon May 30 19:31:24 2011 ***
Traceback (most recent call last):
  File \"/usr/share/whyteboard/whyteboard/gui/frame.py\", line 264, in on_save_as
    _file = _file.replace(u\":\", u\"-\").replace(u\"/\", u\"-\")
UnicodeDecodeError: \'ascii\' codec can\'t decode byte 0xce in position 20: ordinal not in range(128)