You might try tinkering with the refresh rate as well. Make sure there's not some patch for DirectX that you're missing perhaps. There's a DirectX diagnostic that you can run. Under XP, its called dxdiag.exe  I would think that Media Center would be DX11 compatible but some games aren't and may require the latest DX9 files according to this info I found. I have no idea if that's part of your problem.

www.sevenforums.com/gaming/77293-tips-troubleshooting-game-issues.html

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