aprospere
We have had some compatibility problems with some Geforce 4 MX 440's and the ECS K7SEM
Also have you disabled the onboard graphics in device manager and set first display to addon AGP card in the bios.
Plus all the normal driver updates: DX9b, 53.03 Detonators,
SIS platfom drivers, fully updated Windows, plus any patches for the particular game you are trying to play.
Also consider a bios flash if all else fails.
Martin
Replying helps further our knowledge, without comment leaves us wondering.