OSX Mountain Lion: Automatically restarts after showing screen saver a certain amount of time Since I upgraded to Mountain Lion it happens to me every day when I enter the screen saver while having lunch it tries to restart the computer.

I don't have any clue why this happens. If there is some process running and OSX can't automatically quit it, OSX will tell me that it couldn't restart. 
But if there's no process like this running it will restart.

I don't really want this behaviour and searched in system settings as well in the Console in order to see why this might happen but I don't have a clue as of why.

OSX Mountain Lion 10.8.2 - MacBook Pro 15" Late 2011
Ok well. After getting more and more annoyed, I finally figured it out.
Apparently I enabled the automatic logout after 60mins of inactivity in the security settings. I really don't know why/when I enabled this and wouldn't consider myself a noob ;)
For anyone else looking for a howto on this:
http://support.apple.com/kb/PH4014 (I found this page and thought: that must be it!).. It was.