I too am having the same problem. If I put the video card (HIS IceQ) into the pcie 4x slot it works fine. If I stick an old 2.0 card into the x16 slot it works. The only fix I have found online was to boot up the card in the 4x slot, flash the bios, then put video card back into the 16x. While this is a temporary fix, it reverts back to same issue upon reboot. Any help would be greatly appreciated.