After I shut Firefox down, when I try to re-open it (in the same session) I get message "Firefox is already running but is not responding. To open a new window, you must first close the existing Firefox process or restart the system." So I would restart the computer, and it was ok until I shut down again. Finally I used TUT to see what was running in my programs and found that Firefox WAS still running, even though no obvious pages were open on toolbar, etc. Now I use TUT to shut it down instead of restarting, but it's still a nuisance. Should I reinstall Firefox?