Comment 9 for bug 534519

Can someone test this with a new profile to see if this is in fact due to an extension? You do not need to delete your old profile to test. If this helps, you might want to try to disable all your extensions and re-enable them one by one until you find the problematic one (which may be NoScript from the sound of things).

You can start the profile manager with the following command:
firefox -ProfileManager