I have been using multiple browsers successfully for years, but now I seem to have run in to a problem. When I run firefox or IE, they appear to start up, but the mouse pointer just permanently turns into an eggtimer, and I can do nothing else with them. Task manager shows them as "not responding". I then have to use task manager to "end task". I tried re-installing firefox, but that made no difference. Google chrome works fine. Any ideas what could be happening?