Try resetting the BIOS using the jumpers on the Mobo; check all the clock and memory settings are correct for the processor and memory; and if you can flash the latest firmware to it. If the problem persists and you ahev more than 1 stick of RAM in it then try with just one stick then the other.
Will try these and report back.
EDIT: Pulling out the mobo jumper/pin worked the trick.
You sir are a genius.