I have been quite pleased using V3.6.10. It works and my extensions/add-ons work. I tried installing V8.0.1 and, though great promises are made about the new functions, etc., it killed-off my add-ons. The Add-on screen causes FireFox to lock-up when I try to use it. Though there is a warning given about certain add-ons not working in V8.0.1, the others don't work and nearly all the icons on the Add-ons screen disappear, even for the ones that should work, but do not. I re-installed my older version and had to re-acquire almost all of the previously installed add-ons in order to get them to work, again. I don't understand pushing people to upgrade to a version that causes so much trouble. Although, I may like some of the new features, I do not want to lose the old ones!