cant play prince of persia warrior within

Ive installed this game come to play it and it runs a test to see if my system is capable of running the game my system is well within the specified parameters but on the graphics its got a red cross saying that it needs a 64mb card minimum but I have a 128 radeon 9550 installed so what’s the problem ive got the drivers installed ive tried new and old drivers but I still have the problem also on other games the graphics are slow anyone got any ideas plz??????