This is with gnome-session-2.23.5-0.2008.07.21.3.fc10
Will attach .xsession-errors.
Created attachment 312603 [details]
Also, I'd try gdb to get a proper stack track but am unsure how to properly
debug this - hints welcome. Thanks.
mclasen fixed this in gnome-session-2.23.5-0.2008.07.21.4.fc10
*** Bug 456633 has been marked as a duplicate of this bug. ***