I'm experiencing the same issue on my UD3H with F8g BIOS. Was not occurring with the F8 -26.Apr 12 BIOS.
I'm finding it a struggle to reach my previous 4.4GHz @ 1.325v overclock with this board. I fear overclocking degradation is the culprit but I'm not sure eight months at that level/voltage would do that. I might purchase a 3770K just for the thermal savings anyway because the temperatures I'm getting while trying to stay silent are unacceptable. It seems a few people are buying those AIO water cooling solutions from Corsair, Antec, etc. but I wonder if the pump noise is going to piss me off. Already kinda pissed that my NH-D14 isn't performing as well as I'd hope.