I am almost betting the world that this is due to the drivers or fimware (built into the card) causing these issues. I did have a ATI 650 something or other card and it had issues in Vista (even though they stated it was Vista certified). It was all due to the way the OS seen the card. After talking with ATI I found out it was the micro code or firmware that was causing my issue. They then told me it was Vista certified, but between the OS and my mainboard it was being reported wrong to the system.
I took it back and made the chain store give me my money back. Then i just put a TV and DVR in my computer room. It cost me more, but my PC is not being used (proccesses) for the tv and recording.