Pertaining to the system.log's "Previous Shutdown Cause:" entries. In short, my MBP has a cause of "0" most of the time. In my previous careers in programming and systems work, I'm assuming that's similar to an exit code and should be "good." However, occasionally I get a cause of "-72." This is accompanied by random shutdowns, usually 0.5 to 3 seconds after boot (during the gray power up screen). I've tried searching for a listing of codes on this site, Apple's community forum, and on Google to no avail. I'm curious to know what the "-72" signifies. (Yes, I do have AppleCare, and in fact just got it back from Apple less than a month ago for an unrelated issue. I'd just like to have as much information as possible before calling them again).