Ubuntu 12.04. Latest (?) Gnome ... Periodically my background screen when using Mozilla Firefox will grow grey, then a little more grey. It does not go black. But during this time my mouse becomes unresponsive. I sometimes even have to reboot by powering off to regain control. Has anyone else had this type of an issue? Sometimes it recovers by itself, sometimes not.
Please pardon me if I am not in the correct forum.