Well I doubt that it's an SLI board since it's an ATI, but i'd say try reinstaling the drivers, and also maybe physically removing and reinstalling the board, maybe it just didn't get seated in the slot properly or something, and if that doesn't work just try getting a different board.
Edit: If it is the card you should try to RMA it, or better yet just return it to wherever you bought it for a straght replacement, you shouldn't need to buy a different card unless you bought it from somebody else.