Comment 2 for bug 331436

Thank you for taking the time to report this bug and helping to make Ubuntu better. Could you please try to reproduce this using a new firefox profile?:

Start Firefox by entering the following command is a terminal: firefox -ProfileManager. You should now see the Profile Manager window.

Important note: From the Profile Manager you are also able to remove and rename profiles. Be very careful when deleting profiles, if you created the profile in a directory that already existed, the entire directory will be removed!

Click on the 'Create Profile...' button to start the 'Create Profile Wizard'. Click 'Next' and enter a descriptive name for the new profile. Click Finish to have Firefox create the new profile. You should now be taken back to the Profile Manager and the newly created profile should be listed. Select it and click 'Start Firefox'. Try to reproduce the bug with this new profile.
Which Firefox extensions do you have installed?

This will greatly aid us in tracking down your problem.