A word of warning, if you had a beta version of FF3 but used FF2 as your main browser delete all components of the beta before installing FF3. I didn't and it took me ages to find out that it imports the profile from the beta and not FF2 so all my bookmarks were out of date and the means of restoring to a back up bookmark file is different than in FF2. (they don't have the same names or extensions.)
Apart from that it works fine for me .