I have no end of problems with my ATI X1950 Pro, its forever crashing and other I believe card related problems.

As for Vista, I have Vista home premium, Athlon X2 6000+, 3GB ram and rendered a 4.4 billion poly scene the other day, had no problems with it apart from it slowed the system down a bit.

Cheers
Jon

DA Portfolio - http://jonj1611.daportfolio.com/