Since updating to the latest version of Firefox I've received the message whilst browsing: Firefox has encountered a problem and needs to shut down. This never happened with the earlier versions. Has anyone else received message?
go to add/remove programs and see if you've still got the previous version installed. If you have remove both then reinstall 1.04. Firefox doesn't upgrade cleanly and all previous installations need to be removed first. All your bookmarks and settings are retained in a separate folder and will not be deleted so when you reinstall all your settings are there.