Ok, I was always used to my old PowerBook fast sleep (without writing a sleepimage), so when I got my early 2008 MBP (non-unibody), I set the hibernatemode to 0 (default for new MacBooks is 3, which writes out a sleepimage file to HD, the size of your RAM). So this has been fine for a couple years, but on March 4, it changed back to 3. Does anyone know what causes this random reversion of hibernatemode? I've recently upgraded my HD and my RAM, so maybe that did it (I actually changed my RAM on March 2, and tested it on March 3), but was just curious if anyone had more insight. Since I have a large amount of free space, I might just leave it in 3.