Comment 1 for bug 309656

Confirmed under Jaunty. The steps above are reproducible; all you need to do is have Firefox open with several tabs, update it with Update Manager, then quit as per the notification instructions. Clicking "Exit" from the File menu won't bring up the "Do you want Firefox to save your tabs" dialogue, and on the next start you won't have any tabs.

Strangely, if you "killall firefox" right after an update it will recover all your tabs without a hitch. Although it does sometimes bring up the redundant "Your browser has been updated and needs to be restarted" toolbar, which would have been nice to have in the first place since it also saves the tabs.