If you reinstall I think it keeps the configuration data. You may need to make backups of your bookmarks/extensions, then delete DocsandSettings\Username\Application Data\Mozilla after you uninstall to make sure everything is cleaned out. Or could just be Windows being flukny...
On a (possibly) related note, something strange happened last night: I was just typing away in Word when out of the blue my Explorer theme reverted to Windows classic, wireless disconnected, and several other odd phenomena transpired. Explorer went back to the correct theme pretty quickly, but then DirectSound didn't work. Eventually I went to check on Services and found a bunch of them had stopped, including Windows Audio, so I started them again (I couldn't restart or I'd loose my 50+ Firefox tabs I'm using for a research paper.) Now after bringing it out of hibernation this morning, certain programs like Thunderbird won't launch at all...
