first, open your neo550 manual. put your hardware on the right rails. ie video card on its dedicated rail and etc. that will eliminate variable #1 undervoltage.
second is variable #2, check your mobo temp. if it loads at 50 then the answer is simple. put your finger on your NB. if it burns you (which i think it will) then buy a 25$ NB cooler. don't skimp an get one of those 5 dollar aluminum zalmans. and yes you must take off that ridiculuas NB heatpipe. if you examine it, you will notice it is not working anyway.
third, replace that SB heatsink with a cheap 5 dollar zalman chipcooler from newegg.
fourth, if you are on stock cpu stock cooling, stop it. get a asetek microchill, tuniq tower , BT (watch out for space reqs), if you are short on cash settle for an artic freezer pro. of course don't forget the AS5
Thats it. put your bus termination voltage at 1.2. Play with your cpu volts and you will soon be at 3.6 -if you want more, go water cool.
lastly and very importantly, your corsair uses promo chips. leave him alone. run him at his stock speeds. 400 bus with stock timings. He cannot overclock. his range is +/-10%
reason: sometimes people get xms2 6400 with micron chips (thats how they clock it up) if your mem is fast and stable, leave him alone and let him work.