update-manager crashed with AttributeError in initCache(): 'MessageDialog' object has no attribute 'vbox'

[Michael Terry]

Opened update-manager and got this.

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: update-manager 1:0.152.5
ProcVersionSignature: Ubuntu 3.0.0-5.6-generic 3.0.0-rc7
Uname: Linux 3.0.0-5-generic i686
Architecture: i386
Date: Wed Jul 20 16:36:06 2011
EcryptfsInUse: Yes
ExecutablePath: /usr/bin/update-manager
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110422)
InterpreterPath: /usr/bin/python2.7
PackageArchitecture: all
ProcCmdline: /usr/bin/python /usr/bin/update-manager
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
PythonArgs: ['/usr/bin/update-manager']
SourcePackage: update-manager
Title: update-manager crashed with AttributeError in initCache(): 'MessageDialog' object has no attribute 'vbox'
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare vboxusers