thats really odd..
I had the same problem with the same settings and orthos going BSOD on my arse at 462.5x8 3.7ghz....
what are your bios settings, got mine stable for 8hrs with a significant Vcore increase.. it will still bsod at that speed if i leave it going for 10-20hrs.. I havent played with the gtl ettings at all, maybe I should.