I have an Asus EN7600GS 512mb and when I try to run games that use DX9.0c all they always crash after the load screen. The games in question are CS:Source, Company of Heroes and Lara Croft Legends. I can get CS:Source to run by forcing DX8.1, but the other two I just have no luck. I have patched all programs (where applicable), done all windows XP MCE updates, and using latest drivers for the sound, GPU and mobo.
In the dxdiag it gives no problems found, and all the tests work ok.

Has anyone got any ideas?

A side point is that with the latest drivers (forceware 162.xx) my video playback in MCE is "shuddery". The early 94.64 drivers fix those issues, and make no difference to the gameplay. (Not a major issue, unless it affects the games, but it don't)