GA-X38-DQ6 double post after disconnected from power.

I always disconnect power to my PSU by turning off my power manager when I am done with my PC for the day. The first time I boot the PC after re-applying power to the PSU the PC will boot for a second, sound a post beep, turn off for a second, turn on a second time, sound a post beep for a second time, and then boot normally.

Any subsequent cold boots only post once as long as I do not disconnect power to my PSU. Why is my motherboard double posting after disconnecting and re-applying power to the PSU?

My X38-DQ6 also leaves my optical mouse light on when I turn off the PC if power is still available at the PSU.

For sure, P35 chipsets double boot after Bios changes. I don't know about X38, but I'm inclined to think Intel would do them the same way since they were created back to back. So perhaps the battery on your mobo is a little low and when you re-apply power from the PSU it thinks something changed? Or perhaps the loss of 5v from when your PSU is fully off is having that effect.

Just got to ask ...
Your "power manager", does it have a pass-through (always on) AC connection that the pc is connected too?
Is the battery in upsidedown? (I never took notice if this could be done)

I just tested my X38 and I noticed that the double post after being disconnected from AC power only occurs when I overclock my Q6600. It does not happen when I run the stock CPU FSB Frequency and Memory Multiplier.

When I run the stock clocks it only posts once and boots right up after being reconnected to AC power. I think Scotteq was right, it appears to be updating the BIOS when I cold boot after losing AC power while overclocking my CPU.