Occasionally I'll get vram artifacts in W7, this started when I replaced a random DLL a month or two ago so I had reinstalled windows back then; it cropped up again today at like 2AM. If I run the artifact scanner in ATI Tray Tools for an hour or two it still says "0 Artifacts". It seems to happen at random so I'm thinking I should chuck my PSU and card at a wall...any advice? Or am I on the right track? Should I go for a HD4870 or a HD5870 if I replace it? If I go with a HD5870, what kind of PSU would I need? I've been looking at Silverstone & Ultra PSUs. Also going to look at some Seasonics..