I think #2 is right, the weather applets are the culprit. I've also got
two and they do disappear after killing gnome-panel for me as well.
Removing them seems to solve the problem, at least so far I haven't
had any more cases of it hanging.
--
gnome-panel hangs on login
Public bug reported:
Binary package hint: gnome-panel
After upgrading to 9.10 from 9.04 gnome-panel hangs ~80% of the times
when I log in. The panel is drawn but it is completely empty and doesn't
respond when I click on it. I have to do CTRL-ALT-F1, log in, and kill
it to make it reload. This
** Attachment added: backtrace
http://launchpadlibrarian.net/35688018/gdb-gp.txt
--
gnome-panel hangs on login
https://bugs.launchpad.net/bugs/482690
You received this bug notification because you are a member of Ubuntu
Desktop Bugs, which is subscribed to gnome-panel in ubuntu.
--