oh, same problem with mine, i have ocz 12800 on q9450. if i run default cpu 2.6 with 1333 ram, ratio 1:2 no problem
if i raise FBS 400 and DRAM 1600, it crash my windows random, fails any test i tried.
After i OC my cpu to 3.5Ghz and lower dram 1200 ratio 3.4, its work just fine
So i think u never gonna be running full speed cpu 3.2ghz 1600mhz ram , it will crash.
have to kill one and take one either ram or cpu.\
just my opinon cuz i been digging on google for months but now i gave up, i chose cpu over ram. ( 1200mhz ddr3 with 3.5Ghz cpu still a good number for me anyways)