Macbook logs off, tries to shut down after period of inactivity
After about 10 minutes of no use my Macbook Pro OS X10.7.5 logs me out. Sometimes when I go back to it it says it was unable to shut down because programs are open. This happens even if I close Safari, so it isn't a Safari fault. I tried leaving a game app open but it did the same thing. In System Preferences / Security it is set to sleep after 1 hour. Any suggestions please?