emesene crashed with TypeError in _on_extension_changed(): 'NoneType' object does not support item assignment

[jeff E]

new chat window causes error, does not show up.
Same with Empathy.

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: emesene 2.11.4+dfsg-1
ProcVersionSignature: Ubuntu 3.0.0-8.11-generic 3.0.1
Uname: Linux 3.0.0-8-generic x86_64
NonfreeKernelModules: wl
Architecture: amd64
Date: Mon Aug 22 10:53:41 2011
ExecutablePath: /usr/share/emesene/emesene/emesene
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110821)
InterpreterPath: /usr/bin/python2.7
PackageArchitecture: all
ProcCmdline: python /usr/bin/emesene
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
PythonArgs: ['/usr/bin/emesene']
SourcePackage: emesene
Title: emesene crashed with TypeError in _on_extension_changed(): 'NoneType' object does not support item assignment
Traceback:
 Traceback (most recent call last):
   File "/usr/share/emesene/emesene/gui/gtkui/Preferences.py", line 790, in _on_extension_changed
     self.session.config.d_extensions[category] = identifier
 TypeError: 'NoneType' object does not support item assignment
UpgradeStatus: No upgrade log present (probably fresh install)
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 Ubuntu better. This particular crash has already been reported and is a duplicate of bug #729124, 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.