Seems that somehow my FF install was corrupted so after messing around with it and not solving the issue I simply uninstaller it, rebooted and installed a new copy. So far so good. Now when I shut down FF it seems to close okay but when I try to launch it again I get an error message saying "FF is already running, but not responding. To open a new window you must first close the existing FF process....". I have to Ctrl-Alt-Del and shut down the FF process. Any idea why this is happening.