I originally ran this mobo with Opteron dual core 2200 cpu even though my bios (early) was for an AMD Athlon. I was able to OC it until about a year ago when I started to have occasional BSODs so, I backed it off and it has been working perfectly until now. All of a sudden it started crashing again, so I slowed it down some more (about 10x, or 2000). All was well until, I went to Asrock, downloaded a new bios to use the Opteron, and ordered a new Opteron 2400 cpu. Now, I can't OC it at all, and it won't boot into Window(XP) unless I disable the dual core. Asrock won't help.