Damn. I think the boards FOOBAR
I just tried running memtest on the second dual slot and I encountered 310 errors in 2 passes. This the same stick that had 20 passes on the first dual slot with zero errors. To double check, I put the other stick in and it wouldn't even POST, let alone let me try memetest.
So I think it's fair to assume the board was faulty to begin with?