Checking the CPU support page it seems the best you can do is a Pentium D 960. So yeah no BIOS support for the chip means no boot. ASRock has a similar board, and they support C2Dous by forcing the VIA chipset to overclock the FSB and memory controller. Since the board can't stably go all the way to 1066 tho it simply stops short around 1050 or so, thus under clocking the chip. So yeah, I guess Asus didn't want to put that half assed support in their board only to have some n00b complain to them about the underclocking.