Both of my two rigs blue screened a lot over the weekend, more so yesterday. I had to decrease one rig to stock voltages and reduce the overclock from 3.8GHz & 2.4GHz [NB Freq.] to 3.6GHz & 2.2GHz which decreased the temps a lot and the other from 4.0GHz & 2.8GHz to 3.8GHz & 2.6GHz.
I wasn't too impressed but i've come to the conclusion that it might be possibly better to overclock on stock voltages rather than increase voltages, i'm using a Corsair H50 btw.