I've had a couple of PSU blow up and it seemed to be related to unplugging the power lead before the network cable because it also blew the onboard LAN at the same time.
My theory is that the capacitors hold a lot of charge and if you switch off the computer and unplug the power cable it tries to earth down the LAN cable!
My Quad 9300 just arrived while typing this. Got it of ebay for £138 hope it works no motherboard to test it in yet so will be another 24hr before I know if I've been ripped off with something dodgy
DinoHunter (still no nVidia compo voucher!), CPU/GPU Benchmark, DarkFish Encryption DLL, War MMOG (WIP), 3D Model Viewer