Nugzo/Bootsy,
This is just a suggestion but is there any chance that the PSU is playing an issue when the Quad Core is installed? I realize that sounds crazy given your Thermaltake supply/Silverstone supply but as many have already realized the boards are a bit finicky when it comes to PSU's? Plus an issue with the power supply might cause the type of issues your having (shut down)? With that said what supplys are you guys using that have successfully run Quad Cores on this motherboard? I can imagine how frustrating thsi would be so I'm just tying to help out! Good luck guys and keep us posted on progress!