I've been banging my head against the wall trying to get my Blood Iron mobo to crack 600mhz on the memory side, with what I thought were some nice Tracer 8500 sticks that I got on close out sale late last year. Finally took out my old PB5-D for a run and seems like they like that mobo more. Easy 600 at mostly auto and 2.15v.
http://img182.imageshack.us/img182/6...defaultwj4.jpg
Will go to 620 with 2.25v but moving off strap at 400 bus speed sends Pi performance into crapper. :(
I have another pair I need to test before I try 4x1Gb set-up.