I just re-installed 3.16.6 as I really don't like the new version 4. I had this link recommended and although I only did it 10 mins ago it seems to be working fine: http://www.mozilla.com/en-US/firefox/all-older.html You'll need to choose the version you want from the list, I chose 3.16.6 as it was the most recent version that isn't Firefox 4.

fixed link as oldapps in not official.

I understand your anguish, I have some serious issues with version 7 in that the top 2 inches of the browser is locked out thus not allowing me to either Login or Logout from sites. Plus Java and windows Vista scripting does not work. So i am looking for version 6 which does work, do you know where I can get it?