Well 1.70 has an update for the microcode 6F7/66 which apparently is used by my QX6800 so you might be on the right track. Maybe next weekend, I'm somewhat tired plus dinner isn't going to make itself. Anyway, I believe it was my RAM. I don't know what I did but I can't get it stable to 215 CL2.5 again. Still works fine at <200 (3:2). Or it could be that 1.60 is less tolerant to some RAM modules; I have another set of DDR500 RAM (OCZ too) and the board wouldn't boot up with them. Seems to like my DDR400 CL2.5 just fine though.