Whenever I open FF (1.5.03) now I first get a progress bar saying "Checking Configuration" followed by a page saying "Ther is a new version of FireFox". I have tried Preferences, and every option available and I cannot turn the damn thing off! If I close FF and then reboot it, the same thing happens.
Have you tried following setting:
by removing the ticks from in the panel?
I am aware that many Mozilla browser users are university/college kids with an attitude of open-source is the only solution... many of them can't survive without the latest updates or patches they can get hold off.
I ranted this in my forum (
link).
Otherwise, try creating a new Firefox user profile and see if that helps.