... bad driver or bad card? Well, I have been tryin to sort this problem out for months now, since I got the card in fact. I finally decided I needed to ask some folks about it, and this place has always been a good source of info for me, so I finally registered. I have a Gigabyte HD 5870 1024 MB. Default clocks of 850/1200. When I playback HD video or encode something in HD with Windows Live Movie Maker the driver will eventually hang up, causing the screen to stop responding to commands right away. There was a workaround posted here to create a CCC profile and set the base clocks to something higher than PowerPlay's default 157/300, and I've done that. That seems to help, but I wonder why I should have to do this at all? I know that for a lot of people PowerPlay works just fine, so what am I missing? For reference, here's my machine specs. MB: Asus M3A78 Pro (AMD 780G) Mem: 4GB Corsair XMS2 at 800Mhz. CPU: AMD Phenom X4 9750 GPU: Gigabyte Radeon HD 5870 (GV-R5875D-1GD-B) I know, the card is CPU limited, that'll change soon. I am just trying to figure out whether I have a remarkably common problem, or whether I should RMA the card. Any of your help would be appreciated.