[Bug 32802] gnome-panel fails to stop on logout in Dapper (6.04)

[Draconicus]

Public bug reported:
https://launchpad.net/malone/bugs/32802

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

Description:
gnome-panel fails to stop when a user logs out.

This results in a number of other problems. It's impossible to log in again without a big mess. An error will pop up: "I've detected a panel already running and will now exit." - This leads to a lack of any panel whatsoever. 
I tried killing gnome-panel after logging out, and when it started again (when I logged in), most of the applets were unresponsive, and a couple of them, namely the ACPI battery monitoring applet (this is on a laptop) crashed or didn't start. This error has been reported from other people on other systems.

I now have to reboot to check session changes, apply new X
configurations or anything like that. This could be considered a serious
problem.