Ok in my b/w rev. 2 450mhz I have 4 sticks of pc133 ram... 4 256mb cards... but when I go to see how much ram is has in "about this mac" it shows I have 640mb of ram... \ In system Profiler it shows DIMM0/J19 size 128 DIMM1/J20 size 256 DIMM2/J21 size 128 DIMM3/J22 size 128 All cards are ValueRAM brand PC133 Does it matter if they are one or dule sided? Or what ?? hmm is there some kinda trick to this? Thanks!