maks@ubuntu:~$ sudo dpkg-reconfigure software-center --force
[sudo] password for maks:
Updating software catalog...this may take a moment.
INFO:softwarecenter.db.pkginfo_impl.aptcache:aptcache.open()
Software catalog update was successful.
maks@ubuntu:~$ software-center
2012-09-13 22:24:01,370 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None'
2012-09-13 22:24:01,373 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True
2012-09-13 22:24:01,588 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file
2012-09-13 22:24:01,687 - softwarecenter.ui.gtk3.app - INFO - show_available_packages: search_text is '', app is None.
2012-09-13 22:24:01,999 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open()
Traceback (most recent call last):
  File "/usr/bin/software-center", line 176, in <module>
    app.run(args)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1422, in run
    self.show_available_packages(args)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1352, in show_available_packages
    self.view_manager.set_active_view(ViewPages.AVAILABLE)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/session/viewmanager.py", line 154, in set_active_view
    view_widget.init_view()
  File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/availablepane.py", line 171, in init_view
    self.apps_filter)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 238, in __init__
    self.build(desktopdir)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 511, in build
    self._build_homepage_view()
  File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 273, in _build_homepage_view
    self._append_recommended_for_you()
  File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 481, in _append_recommended_for_you
    self.recommended_for_you_panel = RecommendationsPanelLobby(self)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/widgets/recommendations.py", line 160, in __init__
    self._try_sso_login()
  File "/usr/share/software-center/softwarecenter/ui/gtk3/widgets/recommendations.py", line 224, in _try_sso_login
    self.RECOMMENDATIONS_OPT_IN_TEXT)
  File "/usr/share/software-center/softwarecenter/backend/login_sso.py", line 164, in get_sso_backend
    sso_class = LoginBackendDbusSSO(window_id, appname, help_text)
  File "/usr/share/software-center/softwarecenter/backend/login_sso.py", line 48, in __init__
    'com.ubuntu.sso', '/com/ubuntu/sso/credentials')
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 241, in get_object
    follow_name_owner_changes=follow_name_owner_changes)
  File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 248, in __init__
    self._named_service = conn.activate_name_owner(bus_name)
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 180, in activate_name_owner
    self.start_service_by_name(bus_name)
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 278, in start_service_by_name
    'su', (bus_name, flags)))
  File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 651, in call_blocking
    message, timeout)
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.Spawn.ChildExited: Process /usr/lib/ubuntu-sso-client/ubuntu-sso-login exited with status 1