I have a similar problem. Mind you, I also have a DirectX 9.0 installed.
I can't run MW with my new Gigabyte RadeOn 9700Pro, the game crashes when I try to exit buildings into the open spaces. I already tried reinstalling the drivers, installed the latest version of Catalyst (5) but it only made things worse. I was able to run around a bit in the wilderness (5minutes) then the game crashed again and all the other 3D applications refused to work properly. Now I put the older version of Catalyst so everything else works now, not MW though. HELP!