mac pro tower 5.1, system 10.10.5... Every few minutes the user logout kicks in and if I am not there to stop it it shuts off all programs and puts the computer to sleep. Nothing in the system preferences box has any effect... time to sleep, hard drive sleep, screen saver... I want to completely disable this crappy feature. I ruins my ability to process work over more than about 5 minutes if I am away from the computer to arrest it.