Maybe the speed of the RAM is fine, but the timings need tweaking? Perhaps you need to loosen one or a few of them to get it stable. Did you ever run Prim95 or Orthos at lower CPU clocks that seemed stable?
Also, the RAM could be craping out--unlikely, but a possibility. Could run Memtest86 upon boot. Just a few suggestions.
Or the OC is just unstable that high, and has nothing to do with the RAM, though BSOD's are indicative of RAM issues. Could be your PSU isn't beefy enough? I didn't look at what your PSU is before typing this, so if it's fine, then disregard that idea. Hmm...
EDIT--yeah, upon closer inspection, your PSU should be fine.