I had this problem, and found I was running a Quinnstorm upgraded gnome- terminal. Downgrading to 2.14.2-0ubuntu1 from dapper-updates has fixed the problem.
-- gnome-terminal crashes on breezy after some time https://launchpad.net/bugs/23480 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
