Got my black MacBook in June and immediately replaced the 512 megs with 2 gigs of RAM. I used occasionally without problems until August when sometimes instead of starting, the sleep light came on and the screen stayed dark OR I would get the startup chime repeatedly with a plain lit screen until I shut it down. These problems happen less than 5% of the time. Also in the last month or two, it has given me 2 or 3 kernal panics. These problems don't seem to be the Random Shutdown Syndrome because the machine is cool and has never quit when hot. I'm thinking that the two gigs of RAM I installed could be the problem. I switched them around and jammed them in but maybe one or both is defective. Is there an easy way to test RAM. Removing one gig at a time would be hard to test because my problems happen less than 5% of the time. Again, any easy way to test RAM? Would an Apple store have RAM test equipment? Tom Miller