I am having a problem figuring out the orientation of my memory installation. I have four slots. Two of one color and two of another. I assume that means something but nothing is mentioned in the owners manual. In the manual, the guide shows a layout that makes no sense to me and does not correspond to the colors. I have 2 one gig pieces I am installing. I am tempted to buy 2 more and just fill up the slots. Does anyone know in what order these memory boards need to be installed?