2.9 VDIMM unstable

At 2.8 vdimm I can get my memory to pass memtest at ddr416. If I try upping the vdimm to 2.9 i can't pass memtest at ddr350(stock speed). Could it be something wrong with the motherboard or does the ram just not like voltage?

Edit: I moved one of the sticks and now 2.9 seems to be stable. They are now in the two outer slots.

No more dual channel then

Sorry I don't have a solution but just thought I would mention that I found a simular problem with the vcore, @ 2.15v it is fine.. 2.2v it is flakey and at 2.3v it doesn't run stable at all even at stock speeds as well. Maybe they fixed this problem on the v2.0 boards though...

how does this work if I am trying to run tighter timings at a higher fsb are you supposed to raise the voltage to your ram or what? basically I'm asking like a cpu you raise fsb or multi then you raise voltage to get stability is it the same with ram the higher speed/tighter timings = more voltage?