I'm having exactly the same problem with the DX58OG board! Did you find any solution?
Could it be that your BIOS jumper on the board is in the wrong position?
I discovered that the "B2B" pushbutton can look as if it is not active but in reality is activated due to slight pressure from misalignment of motherboard to the IO plate in the chassis. I reseated the motherboard and taking care that the B2B button was NOT touch anything and was able to place the motherboard into normal operation.