Complete Freeze Ups

Just upgraded from SiS 630/730 onboard video to a Sapphire Radeon 9000 64MB DDR card. Now, when I load Soldier of Fortune II, the computer completely freezes on the main title screen. Happens every time. When I load Black Hawk Down, I can get as far as choosing a server to play on and loading a map. However, as SOON as the gameplay begins, I get a complete freeze up and have to hard boot.

Running AMD K7/1.3GHz with close to 400MB memory, Windows98, with DirectX 9.0. Have most current drivers for the Radeon as well. Doesn’t seem to be a heating or power supply problem. Anyone know of any possible problems? OpenGL issue? It’s been suggested that I update my AGP drivers but I have my doubts it will prevent the lock-ups.

Help!

[This message has been edited by jcl49er (edited 03-12-2003).]