Dont forget about Opera! Iknow its not quite as good as firefox,but I love the way you can 'flick't he pages with your mouse instead of having to press back.
Even though,bignanny still has a problem,and it took me some convincing to change browser,it can be a big step.
All I can say is download and install any updates available.Restart computer(to activate some downloads)sometimes the computer initializes these downloads then they actually are recognized by the computer and work!
I am a computer dumbo so that is the only help I can give.Hope it does help
Aya