I recently bought a stick of 1GB from newegg for a little under $200. When I got it my computer froze up right as it got to the desktop or I would get the gray screen of death. So I tried every possible combination of the RAM that I have, (swapping slots, using my dad's PB RAM) It worked fine in my dad's 15" 1.33Ghz PB and it only worked in mine when it was the only stick installed. This is unacceptable since right now I have 2 sticks of 512 and would just end up with the same amount in the end. The computer works fine when I have the 2 512 sticks in but not with the 1GB/512 combo. So I ran TechTool deluxe which came with the applecare package, and ran all the tests and the only problem that came up was a bad block in the hard drive. SO i'm wondering if its the RAM (newegg's problem) or the hard drive (Apple's problem)?