I am (A) not a bit FF fan, and (B) not a big IE slammer. BUT....
FF #2 has been fine; and...
I installed IE7 beta, and had to uninstall it; then installed IE7 final version, and had to uninstall it.
Let me guess, and now you have problems with IE 6 opening blank windows, using new windows instead of current ones, etc. I had that last week after uninstalling 7, and it took me 3 days to track down an answer (which I can provide you, if you wish.)