What board do you have? I literally got my Asus P6T, CPU, and memory yesterday and was toying with it. It was giving me 1066 as well. I tried to manually enter this but there was SO many items to change, I changed the wrong ones and it failed. Find the XMP setting in your BIOS and it will load the settings located on the memory. I found my setting under the Ai Overclock stuff, but not sure what it would be on a non Asus board. But find the XMP setting and you will be good. I think it stands for eXtreme Memory Profile.