GPU Crashes

[glorybound]

GPU crashes are random and occur for no apparent reason. I can render just fine, make no changes, and then render again, only to get a crash. I can render, stop a render to tweak something (maybe move a tree), and everything is good. However, if I move something else, it crashes. I crash 3-4 times a day, easily, and that's time = money. The crashes are always during a render.