Comment 2 for bug 276809

Please, try to run firefox using a clean profile in order to see if the problem comes from one of your extension: firefox -safe-mode

It your problem still occurs, try to obtain a backtrace by following the instructions on https://wiki.ubuntu.com/MozillaTeam/Bugs and http://live.gnome.org/GettingTraces/Details.

Set to incomplete until we have more a backtrace or more info.