Videocards - AMD - ATI AMD Radeon graphics cards. Do you have one or want to buy one? Use this forum to discuss anything concerning products using Radeon graphics cards, CrossFireX, from Radeon 9800 to HD 6900
I'm not very convinced is a overheating issue anymore. I install sensors apps to watch the temp and when I play some games my temp goes to 80-90C but still working VGA doesn't crash.
These crashes occur mostly when I'm watching Flash or a Movie and my GPU temp is around 60-70C.
Just came across this accidentally, if you are still trying to solve this: this is a connectivity issue of the GPU and/or the video memory modules. Reflow is the solution, I just did it last week with my Studio 1555 and worked like charm!
Before it I had the same experience as you, was not overheating and crashing with Flash. (Why Flash I don't know, maybe it uses the video memory much)