Take a look at the System requirements for the card and make sure that yours is fully compliant. Make sure you are using the latest drivers for the card.
http://www.ati.com/products/firegl8800/
How old is the game? Have you tried compatibility wizard (making the computer pretend it is something different). I doubt it will work in this case.
There is a thread on the game forum on exactly this problem. Seems like ATI Cards are not renowned for their brilliance at OpenGL.
Game Discussion Forum Thread
Regards
DeepC