I work for a middle school with an Xserve running Lion server. We have a 1-to-1 MacBook program, so every kid has a MacBook Air to use at school and at home for the year. One has a very interesting issue. Neither AppleCare nor our Apple consultant have been able to provide any assistance. No matter what MacBook I give to this student, she experiences random shutdowns. I have re-imaged the MacBooks in question. I have deleted her home folder and forced it to regenerate. I have deleted her entire user account and recreated it with a different UID and short name. No matter what I do, this student's MacBook always shuts down randomly. And it most certainly is not user error -- both her teachers and myself have witnessed it. I have found a number of different terminal messages in the system log. The one I get most often seems to be along the lines of: Code: 8/29/12 11:11:52.813 AM com.apple.launchd.peruser.2015031: ([0x0-0x1a01a].com.apple.AppleSpell) Exited: Killed: 9 8/29/12 11:11:52.814 AM com.apple.launchd.peruser.2015031: (com.apple.mdworker.pool.0) Exited: Terminated: 15 8/29/12 11:11:52.881 AM com.apple.dock.extra: Could not connect the action buttonPressed: to target of class NSApplication And today a new set of messages appeared: Code: 8/30/12 12:44:26.892 PM com.stbernard.rfcd: [Thu Aug 30 12:44:26 2012.892054][firewall]: Disabled the firewall. 8/30/12 12:44:32.175 PM SecurityAgent: kCGErrorInvalidOperation: CGSOrderWindowList 8/30/12 12:44:32.175 PM SecurityAgent: kCGErrorFailure: Set a breakpoint @ CGErrorBreakpoint() to catch errors as they are logged. 8/30/12 12:44:54.732 PM ntpd: proto: precision = 1.000 usec Does anyone have any remote clue what I can try next?