Bought a mid 09' white macbook. 2.13ghz with 2gb 800mhz ram. The bf has a late 06' Macbookpro with 667mhz ram and i put one of his old 1gb sticks in with my 2gb stick. It at first worked fine. Turned on said i had 3gb 667 then did a lined white screen and had to be shut off. Tried another stick of the ram and worked for about a half hour then the computer displayed a message saying it needed to be shut down and would restart to a black screen and a solid white light. Shouldn't my macbook just work with the slower ram and down the speed of the 2gb to 667? Its almost like the mac likes it one second then its like yeah i'm not liking this anymore and causes problems. Does for some reason my computer just not support that slow of ram or is something else wrong?