i'm on 0.4 and for the past few days it just keeps dropping to ~20 GH/s after going for a hours a couple of hours at most. i usually end up with usb errors and need to reboot the host to get regain hash rate. initially it was dropping hash rate after just a few minutes, but dropping the clock to ~350 MHz allows it to hash for longer (also set fans to 90-99 as temp was near 90C at default clock). i'm wondering if my heatsink might not be on right anymore (recently move the machine). fuck this pos.
Yikes! What hash rate are you getting at 350? Pulling the heat sink off and reattaching is definitely a good idea. You need to clean everything very carefully and make sure you reattach with the right amount of thermal compound. One other thing you have to be careful of is not tightening down too much or you will warp the board.