So whats the game here then ? Do you by chance have one of those dualVsta boards with a PCIE x4 and an AGP slot ?
You see im guessing at these types of things because you have not really given us much to go on. The reason i ask is because these boards usually need Bios updates to support newer cards and tend to favour ATI cards over Nvidia ones for some reason.
If its just a general question then i agree with Timop more or less.