update-manager crashed with AttributeError in _try_show_release_notes_textview(): 'Window' object has no attribute 'window'

[kim howard]

updating from 11.10 to 12.04LTS

message
sorry update manager closed unexpectedly

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: update-manager 1:0.152.19
ProcVersionSignature: Ubuntu 3.0.0-12.19-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu1
Architecture: amd64
Date: Sun Jul 8 20:33:11 2012
ExecutablePath: /usr/bin/update-manager
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
InterpreterPath: /usr/bin/python2.7
PackageArchitecture: all
ProcCmdline: /usr/bin/python /usr/bin/update-manager
ProcEnviron:
 SHELL=/bin/bash
 PATH=(custom, no user)
 LANG=en_US.UTF-8
PythonArgs: ['/usr/bin/update-manager']
SourcePackage: update-manager
Title: update-manager crashed with AttributeError in _try_show_release_notes_textview(): 'Window' object has no attribute 'window'
UpgradeStatus: Upgraded to oneiric on 2012-07-08 (0 days ago)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #859862, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.