PSU flickering leads to GPU failure

Here is a video of what happens: http://www.youtube.com/watch?v=i_W-BM3Vmkk Whenever I try to game longer than 10 minutes on this rig I JUST built, my PSU starts flickering like a strobe light and then my computer freezes. Sometimes it will display a random color though out the whole screen, or just go black. I have checked all my temperatures when this occurs and they are all well below...