Computer shuts down too fast

This happens with an updated Dapper install as of May 20th.

I've enabled automatic saving of the current session in Gnome. If I choose Shutdown from the Log out menu, then every terminal window echoes a message saying that the computer is shutting down (the standard message from running "shutdown -h now"). The problem is that none of the running programs are stopped properly, I usually keep Evolution, Firefox and Straw running along with a bunch of gnome-terminal windows.

(I'm aware that Firefox doesn't support sessions. This bug is not related to Firefox apart from the risk of data corruption.)

When I start my computer again and login to Gnome I seem to get some random selection of programs started, not the programs I had running before the shutdown, and on some occasions Evolution and Straw have lost settings and the read / unread status is messed up.

I think this bug was introduced within the last two weeks, previously to that Gnome and the running programs would be stopped before the machine shut down, thus preserving the session correctly.

vegar$gain [~] dpkg -l gnome-session
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Config-files/Unpacked/Failed-config/Half-installed
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
||/ Name Version Description
+++-==============-==============-============================================
ii gnome-session 2.14.1-0ubuntu The GNOME 2 Session Manager