[apport] update-manager crashed with ImportError in <module>()

Binary package hint: update-manager

just clicked on the updates are waiting icon

ProblemType: Crash
Date: Tue Jan 30 21:34:20 2007
DistroRelease: Ubuntu 7.04
ExecutablePath: /usr/bin/update-manager
InterpreterPath: /usr/bin/python2.5
Package: update-manager 0.53.3
ProcCmdline: /usr/bin/python /usr/bin/update-manager
ProcCwd: /home/jaakan
ProcEnviron:
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/bin/X11:/usr/games
 LANG=en_US.UTF-8
 SHELL=/bin/bash
PythonArgs: ['/usr/bin/update-manager']
SourcePackage: update-manager
Traceback:
 Traceback (most recent call last):
   File "/usr/bin/update-manager", line 32, in <module>
     from UpdateManager.UpdateManager import UpdateManager
 ImportError: No module named UpdateManager.UpdateManager
Uname: Linux DELL7500 2.6.20-5-generic #2 SMP Sat Jan 6 14:50:47 UTC 2007 i686 GNU/Linux