Memory compatibility on P67 seems to be a joke...
I traded ZenEffect my STT 2200 C8 for GSkill 2133 7-10-7 as I wanted a set of PSC to play with on AMD...

My STT 2200 C8 did only 1700 6-6-6-18 on AMD, while my STT 2000 C7 does 1800+...and GTX2 gets up in 1850-1900 land.

I was worried he'd have major problems with it on Sandy, however he has gotten the ram to play along fine at 2133 7-8-7. It's rediculous.