p.s i meant max for the ram not for what the board will go
ok sorry only run the ram at max setting that the ram is ment to run at not what the board will go to that would kill your ram and fast
edit
it's probably going to be anywhere from 2.0 to 2.3v max for those dimms run them at what ocz says is there max safe voltage if that does not solve your problem then check out your southbridge voltage
and after all that is said and done if you have not been able to get it stable then i would run memtest on each stick individually to see if there any problems with them