Traceback (most recent call last):
  File "/usr/bin/gnome-app-install", line 209, in <module>
    from AppInstall.AppInstall import AppInstall
  File "/usr/lib/python2.5/site-packages/AppInstall/AppInstall.py", line 63, in <module>
    from UpdateManager.Common.aptsources import SourcesList, is_mirror
ImportError: No module named UpdateManager.Common.aptsources