There's a huge review database at newegg for that ram and while overall it looks really good, there is also a portion of people who never really had success with the 4-4-4 timings. If you are going to try and keep pushing upward with the clocks you'll have to nudge some of those voltages upward as well. These are my settings for a q6600 @ 3.6ghz:
vcore:1.4675v
cpu vtt:1.27v
mch:1.37
ich:stock 1.05v
ichio:1.5v
cpu gtl ref:61 and 61
Of course every setup is unique to some degree but that should give some reference for experimenting. You may find that going even higher with the mch will help with those corsair timings, I don't know.