Might try raising the DRAM voltage + 0.05 and CPU/NB up to 1.2
Ok, I'll try adding some voltage to the DRAM if you think that'll help stability, even though I haven't OC'd the RAM itself (only OC'd CPU and NB)
In the gigabyte BIOS there isn't anything called CPU/NB, but I am assuming "NB core" is the equivalent? I that case, it is 1.2V stock. Should I try bumping it to 1.25-1.3?