Sapphire HD3850 AGP + Vista = Problems

I've been having these problem for a long time now and i'd like for them to get sorted out finally so any help/suggestions would be appreciated. I recently got a Sapphire HD 3850 AGP card and it works wonderfully on Windows XP, But when I use it on Vista it runs like crap. I have some odd lag when i scroll with aero enabled. Games will have many messed up screens/artifacts. Movies play so choppy its unbearable and lastly nothing will run in DirectX 10. I've tried many different drivers for the card, even the latest ones, yet nothing works. I've got all other drivers installed and up to date on my mobo also. The card is not OCed because my old P4 bottlenecks anyways. These problems are only happening on Vista. Also it does the same thing on Windows 7 if that will help any at all. Thanks in advance!

Thanks for your response but i've tried all of them official,hotfix, etc. I'm still trying to get some answer from Sapphire but so far I've had no luck.

Well Frozenlead I know its something with the video card drivers because ive had an old x1300 Pro in this and Vista ran just fine with it. Its the video drivers thats causing all the headaches. The sad part is is that the card is fairly new...