[Bug 30022] Closing either "Shut down" or "Log Out" windows crashes the panel

[Manu Cornet]

Public bug reported:
https://launchpad.net/malone/bugs/30022

Affects: gnome-panel (Ubuntu)
       Severity: Normal
       Priority: (none set)
         Status: Unconfirmed

Description:
If you open either of the "Shut down" or "Log out" windows, and close it
by clicking the top-right window "close" button (not the Cancel button),
gnome-panel crashes.

This happens on an up-to-date dapper.