restricted-manager won't start!

Today I've installed Gutsy Gibbon Release candidate from CD and downloaded all the updates. After that, the restricted manager won't start! An attempt to start it from terminal would result in:
jheronimus@jheronimus-laptop:~$ sudo restricted-manager
Traceback (most recent call last):
  File "/usr/bin/restricted-manager", line 42, in <module>
    rm = RestrictedManager()
  File "/usr/lib/python2.5/site-packages/RestrictedManager/RestrictedManagerGtk.py", line 53, in __init__
    RestrictedManagerCommon.__init__(self,args,opts)
  File "/usr/lib/python2.5/site-packages/RestrictedManager/RestrictedManagerCommon.py", line 197, in __init__
    self.launch_manager()
  File "/usr/lib/python2.5/site-packages/RestrictedManager/RestrictedManagerGtk.py", line 151, in launch_manager
    self.ManagerWindow(self.xml, self.handlers, self)
  File "/usr/lib/python2.5/site-packages/RestrictedManager/RestrictedManagerGtk.py", line 209, in __init__
    self.reset_model()
  File "/usr/lib/python2.5/site-packages/RestrictedManager/RestrictedManagerGtk.py", line 262, in reset_model
    self.parent.set_title_label(self.xml.get_widget('label_heading'), any_enabled)
  File "/usr/lib/python2.5/site-packages/RestrictedManager/RestrictedManagerGtk.py", line 122, in set_title_label
    (bold, normal) = RestrictedManagerCommon.title_label(self, in_use)
  File "/usr/lib/python2.5/site-packages/RestrictedManager/RestrictedManagerCommon.py", line 242, in title_label
    'these drivers.') % {'os': get_os_name()}
KeyError: u's'