I had the last generation White Macbook, and I upgraded the ram to 8GB. It worked from May 2010 to about a week and a half ago. I swapped hard drives, ram, and still was getting plagued with gray screen messages. I called Apple, and had to wait 5 days to drop off the machine. They held it then for 3 days, and then called me to pick it up. Told me they are not fixing it because I installed 8GB of ram in there, their determination was that the 8GB of ram was the reason the machine broke and they refuse to fix it. WTF?!?!?!