My 15-inch, Mid 2009 MacBook Pro running OS X 10.8.2 mysteriously crashed while it should have been sleeping. Nothing in the Console logs indicate that it was shutting down, and when it booted up it had a lot of (disk) journal logs to replay, so I'm assuming it just crashed.
The only clue as to why is a kernel log entry during boot up: "Previous Shutdown Cause: -81". Does anyone know what this is (and what to do about it)?
61% battery life left when I booted it up the next day, so it wasn't loss of power (and in the past it has hibernated when battery got low anyway).