Memtest and vdimm setting

I am running my system at 11 x220fsb and its stable for the most part. Prime 95 and 3D 2001 will run forever at 2.6Vdimm which shows up as 2.7v in MBM5 at 11-3-2-2 settings.

Memtest will fail test 5 usually with 2 errors on pass 5 and 11 etc.
If I raise the Vdimm to 2.8v it will pass without errors. I know there is some debate about the NF2 boards and test #5
But prime 95 errors out at 2.8Vdimm which is actually 2.9v in MBM ?

Any suggestions or should I just ignore the Memtest errors.

Thanks