hi TankerHC

thats quite a problem you got there.
looking into the hardware side of things too..
maybe there are some electrical ground happening in some other component

maybe check:
1. your video card -- assuming you are using a pci addon card?
2. your lan connection -- maybe test with the lan cable unplugged
3. usb extension wires for the cpu casing
4. cpu casing wires and any additional fans
5. dvd/cd drive?

basically, im also thinking the same thing about connecting as few devices as possible to make sure they are not causing the bios lock-ups.