Although the explanation of the initial power up is a good one. However it doesn't explain why after cycling the PSU it boots up normally. Both nate and I have this issue with this board. And I believe Nate is using a 700w PSU.
I wonder if it's something to do with the chipset? The best way to test our theory is to disconnect the PCP&C unit and connect it to another board. If the same problem happens then perhaps it's a coincidence and we can blame the power supply.