OC'd Memory and Keeps Failing Prime

So with you all help, I am now stable at 4.7. But now I tried to OC my memory to the advertised spec, and it keeps failing prime in like the first 5 mins. Ideas?

System Spec -
i5 2500K - ASRock P67 EXTREME4 - G.SKILL Ripjaws X Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 2133 - MSI N560GTX-TI Twin Frozr II/OC GeForce GTX 560 Ti (Fermi) 1GB 256-bit GDDR5

I'd run it through memtest to make 100% sure it is the RAM that is the problem.

Running 8GB of DDR3-2133 at that speed will require higher VCCIO / VTT voltage. The default is 1.05, so try bumping it up to 1.1-1.20V, and no higher than 1.25V. Also enable XMP Profile #1, auto-setting the DRAM frequency, timings, and voltage to those programmed in the SPD.

I'd start with adding a bit of VCCSA personally, default is 0.920, try 0.960 or so.