Check my sig, built it recently.
I had a memory problem, also took couple starts after taking out the defeact memory. System seems to do a few checks first before finally starting up.
Dont know if this makes a difference, I have used 2x CPU 4pin power plugs, 1x old harddrive 4pin power connection in to the MB for the PCI-e and Pci slots (They say you only need this if all Pci slots are populated)
I use Corsair XMS 6400C4, 1.8v 5-5-5-18, all i did for the O/C was change the jumper on the MB from 266fsb to 333fsb. Didn't need to touch the Bios.
This is my first system to be overclocked
I love the board, I hope you find a solution soon.