I'm a Mac noob (really starting to get a hang of it after a couple days though). I've noticed that once in a while, if I stop using my computer, then go back to it, the desktop is frozen. By frozen I mean it's almost like looking at a screen shot of the desktop. When I move the mouse around, it "erases" the desktop and I can see/click on the login screen underneath. I then have to login again to use the computer. Settings: 2 users Auto login to admin user I've noticed the problem mostly when I use Apple TV to access pics. It then stops eventually and tells me to enable home sharing. I go to the comp, and find the frozen desktop issue again. If anyone has a suggestion I would def appreciate it!