You didn't really say what was wrong, but I'll assume it was horizontal tearing... basically you will always get this no matter what chipset you use. It comes down to how much you are prepared to tollerate vs the facility you get from the alpha blending. Most people, I believe, decide that picture stability is more important and go with UI2 Overlay instead. It isn't a performance thing, it seems to be a driver issue - but has been there for a long time through many different versions of the driver, so don't hold your breath that nVidia will be doing anything about it soon...