Bit vague .... "all kinds of problems" doesn't provide much info as to the 'improvements' you're expecting.

Xircal beat me to it. What is wrong? What have you tried.?

Have you used the Help page and the Search Firefox Help box above? If you work your way through the questions and answers you'll see so many common themes - memory usage, buttons combined and moved, Menu Bar gone or no Firefox Button, problematic extensions, Status Bar gone, Incompatible third party toolbars etc.

Sounds a lot but there are so many easy fixes. With some simple customization and a new theme, I've got Firefox working beautifully and looking good, too.

Do you know about Firefox Safe Mode and New profile as tests for more difficult problems with your setup, rather than Firefox.

I'm just a an occasional passer-by but there are expert volunteers here eager to help. You need to make the effort now or before long Fx3 will not be supported and you'll need to make the jump to Fx5 or 6. I can't see Mozilla reversing many changes.

I hope I've caught the attention of other users, too.