How about Chrome? Chrome is a nice browser and supports Flash. I used it for gaming as both IE 8 and Firefox had problems with that particular game. OR break down and get Windows 7. You will love it - promise!
I got Windows 7 on my real computer. This one has a hard time running Vista Ultimate 64. I'll port everything back when I get a new HD - probably next Christmas 
The thing that hangs me up are the plugins. Things like Speed dial (the real one with tabs - not Opera's puny one) and FTP and AdBlocker (Porn blocker too) So many goodies that Opera just don't have. I can't imagine Google allowing an "ad blocker" type plugin - after all a great deal of their income is web page ads.
I just finished a total wipe of Firefox, total wipe of Flash. First I tried Flash 10 and it failed. Then I tried Flash 11 x64 and it failed even worse. Now I think I will dig up a copy of x32 as I read someplace that Vista 64 is not supported in any way, shape, or form by Adobe and a million others. PLUS they tell me, you are not to use a 64 bit add-on with a 32 bit app.
So...
Sigh...