just found a hiden setting's for the ram an a gigabyte k8vt800 pro motherboard becuase they say that there are limitions on amd64 cpu that cannot us dual ddr400 on a board that only has single ddr slots and it down clock it to ddr333 http://www.giga-byte.com/Motherboard/Support/FAQ/FAQ_444.htmthe link to what they say is here (well there).
the way you get the settings is you boot into bios and then Ctrl-F1 and the setting are in the usall place