the bios does some weird things when its set to Auto set the ram timings.. at first when i booted up my comp it tried running my ram at some rediculous number like 223fsb. Im unsure how i even posted but i did and i got into the bios and set everything MANUALLY to what it should be set to default. so ran voltage was 2.5v, mem timings were 2.5-3-3-7, manually set the cpu fsb to 166 and ram to 166 and made sure my cpu:ram ratio was 1-1. I also made sure my voltage for my cpu at default speeds was set correctly (1.65v).
Try manually setting things to what they are supposed to be at. TELL the computer what to run it at instead of choosing auto, Auto seems to have unpredictable results.
example2) I set my ratio manually to 100% or 1-1 cpu:ram. i manually set my cpu fsb to 166 but left the mem fsb set to auto. SOME HOW it didnt keep 166, it actually raised it to like 168 or something stupid like that. I dont know where it got that number from but it seems the auto features dont always work as planned.
(btw i have the a7n8x as well and im still learning about little quarks it has)