Sorry, this is a newbie question. I understand that RAM on G5's have to be installed in pairs. I'm planning on buying a G5 from Apple with the standard 512 megs of RAM (2 x 256 sticks?) Then I want to purchase 2 x 1 gig sticks of RAM from another vendor. Will this work in combination with the 2 x 256 sticks? I want to keep as many slots open as possible so that I could upgrade to even more ram in the future. Thanks.