Screwy display after screen saver

I recently upgraded my video card and gave my old one to a friend. His motherboard fully supports it and everything, all the drivers and software for the old one have been removed, and I've personally updated it with the newest version of the appropriate drivers for the new card.

However, it seems that after the screen saver comes on, things get weird, and the screen refreshes very slowly. I don't mean the monitor's refresh rate, but rather when windows are dragged, for example, it's very jerky and slow. He says that restarting it resolves the problem, but every time it wakes up from the screen saver, it starts screwing up.

Any ideas what could be causing this?

 

is directx up to date ?
have you tried a earlier version of the driver ?

 

Yes, DirectX has been updated. I suppose I'll tell him to try installing some older drivers, but now he's using the same version I was with that card, so it doesn't seem like that should be causing any problems.

 

The only other things that come to mind are a bios update or bios setting agp 4X 8X etc
There are also nvidia and ati removal tools could try running one of those maybe some reminants of previous card settings or drivers remain

 

I've told him to try these things, so we'll see how it works out.

Thanks for your suggestions.