After my GTX580M died I returned to the original GTX560M that I had but it's also having issue. When I'm gaming it will crash after some period of time, therefore I'm assuming that this is to do with something getting too hot. The screen goes a solid colour (normally yellow or pink), I can hear the sound for a while, on rare occasions the screen will flicker and recover but normally I just have to hold the power button down to turn it off.
FYI M17x-R3, i7 2720QM, GTX560M, 16GB, SDD + HDD, Windows 7 Pro
I've repasted my GPU and CPU, cleaned the vents etc and I don't think the temps are actually that bad. I'll update later with some temps I'm getting. BTW I'm using HWInFo to for the fans to max out.