If you have a TV-out, it could be due to that. My GF4 had a TV-out that allowed Macrovision to be disabled, and while the newer drivers were only SUPPOSED to stop DVD playback on such cards (still sucks that they did that!), it stopped the vast majority of video playback, as well. Luckily for that series, there was no reason to get anything higher than 30.82, though it did make my next card a Radeon :).