Crash when proxy.get_user_gconf

Distribution: Ubuntu 10.04 LTS
Application: Ubuntu Tweak 0.5.7
Desktop: gnome

Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/ubuntutweak/mainwindow.py", line 437, in setup_notebook
    page = module()
  File "/usr/lib/python2.6/dist-packages/ubuntutweak/modules/loginsettings.py", line 53, in __init__
    key="/apps/gdm/simple-greeter/disable_user_list"),
  File "/usr/lib/python2.6/dist-packages/ubuntutweak/common/factory.py", line 71, in create
    return getattr(cls, 'do_create')(widget, **kwargs)
  File "/usr/lib/python2.6/dist-packages/ubuntutweak/common/factory.py", line 109, in do_create
    new_widget = globals().get(widget)(**kwargs)
  File "/usr/lib/python2.6/dist-packages/ubuntutweak/widgets/widgets.py", line 91, in __init__
    self.set_active(bool(self.__setting.get_value(self.__user)))
  File "/usr/lib/python2.6/dist-packages/ubuntutweak/conf/gconfsetting.py", line 149, in get_value
    data = str(proxy.get_user_gconf(user, self.get_key()))
TypeError: show_message() takes no arguments (2 given)