Hi. I have a late 2008 unibody macbook5,1 2GHz. When I got it from somebody else it came with 3GB of RAM and I would like to upgrade to 4GB. According to system profiler my banks contain: 2GB DDR3 1067MHz 1GB DDR3 1067MHz I want to buy "2.0GB PC-8500 DDR3 1066MHz SO-DIMM 204 Pin Memory Upgrade Module" from OWC to upgrade my 1GB slot. Here are my questions. 1.This new RAM is 1066MHz instead of 1067MHz. The manual says to use 1066 MHz.This may sound ridiculous but does the 1MHz make something incompatible? 2. The manual also says the module should be 200-pin while this new module is 204-pin. 3. Is 4GB really the maximum memory I can put on this computer? Would it make any sense to run more? From what i've read it sounds like no. Basically I just want to know how sensitive the computer is/how important it is to match every aspect of the old RAM. Thanks so much.