Overclocking i7 950

So I am in the process of overclocking my new i7 950 with the asus p6t deluxe v2 board and Corasir dominator 1600mhz ram and a clean install of win7 RC. I have been able to get it 100% stable at 3.7ghz with a bclck of 155 a vcore of 1.14v and ram at 1242mhz. But when I go to 4ghz I start to have a little issue. I raise the bclock up to 167 keep the ram at the same setting but it goes up to1334mhz. The vcore i had to raise up to 1.21v. I left everything else auto. I run prime95 and after like 30mins it BSOD's and gives the following error...SYSTEM_SERVICE_EXCEPTION with a code of 0x0000003B......Does anyone know what needs to be changed to make it stable? I googled the code and it usually means a error in the registry or something but that cannot be it. also cooling is not an issue right now i have a TRUE lapped with two 100cfm fans on it and its loads at like 65c in a 25c room. thanks for any input guys.

see the weird thing is that it happens everytime at about 30mins into the test...I will try upping the vcore i dont think its the memory cuz it is running below what its rated at so it should be fine