help with a msi p6n and consair ram

[DaDeadX]

I upgraded my pc using the msi p6n sli mobo, c2d e6400, and TWIN2X2048-6400C4 Corsair RAM. i have the ram running at 4-4-4-12 2.1v when i run memtest86+ on dual-channel mode test #5 errors on me, but single mode one by one the ram doesn't error. 1/3 slots and i tested the mobo slots by rotating each RAM stick on each slot so that isnt it. I also tried 2 sticks on single channel mode and surprise ERRORS! i dont know what do do at this point, rma the mobo and get a new one from asus (had the a7n8x, amd 2400+ oced to 2200MHz) or rma the ram. the reason why i went with msi is the 680i chipset and 2 pata headers (my cd drives and both hard drives are still ide) so help me please? no one on msi forums want to really help me and the tech was rude

 

[KGB]

Have you tried bumping the DIMM voltage up a bit?
Try MemTest86 @ 2.2V in dual channel.