Previously I was using the 100GB version of this in my MacBook and the thing was wreaking havok in my poor computer. When OS X was loaded it would work fine, but at start-up it was causing failed boot-up sequences, instances where I had to reset PRAM to restart properly, and a bunch of other fun scenarios that did not occur when I re-inserted the stock 60GB drive. What I am wondering is perhaps Apple doesn't make 7200rpm drives an option with the macbook (whereas they do with the MBP) because the MB isn't designed to use them? The Hitatchi drive is currently being returned, and I am wondering if is safe to use a replacement of the same kind or if I should buy only 5400rpm drives from the companies Apple uses. I used to think brand and speed shouldn't matter but I am unsure about that now. Anyone have any thoughts?