That's something to do with the graphics card, since in the settings in the Display Panel, you can turn VPU Recover on/off which can fix problems straight away...
Zoomtm might be right with it being a overheating problem, but I'd assume you'd get the same problem on the old drive as well...
Make sure you have up to date video drivers by downloading them from the ATI site, and it might fix it, because since you got the new drive, you probably reinstalled the drivers. You might have just used older ones, because VPU Recover is something in the drivers
Edit: By the way, the newest drivers on the ATI site do not work on my PC for some reason. It might be best you press to get the previous version because I don't think much was changed, but you could always try the newest one. It just causes me to get a black screen when it gets into windows... Least you'd know what the problem was anyway
Hope this helps,