My MacBook Pro restarts after it's been idle for an hour

Question

I'm new to daily Mac use, but I think I have my settings correct. My laptop is kept plugged in at work - never runs on battery. In my Energy Saver system prefs, I have Computer Sleep and Display Sleep set to Never on both Power Adapter and Battery, all options (hard disk sleep, wake for network access, reduce brightness, start up after power failure) are unchecked. There is nothing set up in the Schedule area to turn on or off at specific times.
Every time the computer is idle for more than an hour (when I'm at lunch or in a meeting), when I come back the computer has restarted itself. Not gone to sleep, or shut down, but completely restarted.
Is there some other setting I'm missing that's making this happen? Although I try to remember to save all my work before I leave just in case, every so often I forget, and I'm getting sick of losing work (or even just losing system state and having to restart all my programs, reopen all my files, etc.)
Someone on the apple.stackexchange forum suggested checking my console log, but when I posted the results I didn't get any comments except that maybe it had overheated. But it never restarts randomly, which I would think would happen if it had overheated. It's always tied to the idle time.
Here's the console log for the most recent event; can anyone tell me what's going on?
6/14/11 1:55:10 PM          TransmitFSHelper[4243]          bytes transferred 3881
6/14/11 1:55:53 PM          [0x0-0xfa0fa].com.activestate.Komodo[4306]          fillNetscapeFunctionTable
6/14/11 1:58:28 PM          [0x0-0xd10d1].com.google.Chrome[4095]          2011-06-14 13:58:28.556 Google Chrome Helper[4340:107] __CFServiceControllerBeginPBSLoadForLocalizations received error 1100 from bootstrap_look_up2
6/14/11 3:00:19 PM          com.apple.launchd.peruser.501[4053]          ([0x0-0xcf0cf].com.apple.Stickies[4092]) Exited: Killed
6/14/11 3:00:19 PM          com.apple.launchd.peruser.501[4053]          ([0x0-0xf80f8].com.panic.TransmitMenu[4237]) Exited: Killed
6/14/11 3:00:19 PM          com.apple.launchd.peruser.501[4053]          (com.apple.AirPortBaseStationAgent[4070]) Exited: Killed
6/14/11 3:00:19 PM          com.apple.launchd.peruser.501[4053]          ([0x0-0xfe0fe].com.apple.ScreenSaver.Engine[4496]) Exited: Terminated
6/14/11 3:00:19 PM          loginwindow[3881]          PScurrentwindowbounds: CGSGetWindowBounds returned error (1002)
6/14/11 3:00:19 PM          com.apple.loginwindow[3881]          Tue Jun 14 15:00:19 Web-Devs-MacBook-Pro.local loginwindow[3881] <Error>: kCGErrorFailure: Set a breakpoint @ CGErrorBreakpoint() to catch errors as they are logged.
6/14/11 3:00:19 PM          loginwindow[3881]          _NXSetCursorRect: error getting window bounds (1002)
6/14/11 3:00:19 PM          loginwindow[3881]          _NXSetCursorRect: error getting window bounds (1002)
6/14/11 3:00:19 PM          loginwindow[3881]          _NXSetCursorRect: error getting window bounds (1002)
6/14/11 3:00:19 PM          loginwindow[3881]          PScurrentwindowbounds: CGSGetWindowBounds returned error (1002)
6/14/11 3:00:19 PM          loginwindow[3881]          PScurrentwindowbounds: CGSGetWindowBounds returned error (1002)
6/14/11 3:00:19 PM          com.apple.loginwindow[3881]          2011-06-14 15:00:19.628 loginwindow[3881:107] PScurrentwindowbounds: CGSGetWindowBounds returned error (1002)
6/14/11 3:00:19 PM          com.apple.loginwindow[3881]          2011-06-14 15:00:19.629 loginwindow[3881:107] _NXSetCursorRect: error getting window bounds (1002)
6/14/11 3:00:19 PM          com.apple.loginwindow[3881]          2011-06-14 15:00:19.629 loginwindow[3881:107] _NXSetCursorRect: error getting window bounds (1002)
6/14/11 3:00:19 PM          com.apple.loginwindow[3881]          2011-06-14 15:00:19.629 loginwindow[3881:107] _NXSetCursorRect: error getting window bounds (1002)
6/14/11 3:00:19 PM          com.apple.loginwindow[3881]          2011-06-14 15:00:19.629 loginwindow[3881:107] PScurrentwindowbounds: CGSGetWindowBounds returned error (1002)
6/14/11 3:00:19 PM          com.apple.loginwindow[3881]          2011-06-14 15:00:19.629 loginwindow[3881:107] PScurrentwindowbounds: CGSGetWindowBounds returned error (1002)
6/14/11 3:00:19 PM          com.apple.launchd.peruser.501[4053]          Background: Bug: launchd_core_logic.c:2489 (24498):0
6/14/11 3:00:19 PM          com.apple.launchd.peruser.501[4053]          Background: job_mig_intran() was confused by PID 0 UID 0 EUID 0 Mach Port 0x7703: kernel_task
6/14/11 3:00:19 PM          com.apple.launchd.peruser.501[4053]          Bug: launchd_runtime.c:935 (24003):0: j != NULL
6/14/11 3:00:20 PM          com.apple.WindowServer[4811]          Tue Jun 14 15:00:20 Web-Devs-MacBook-Pro.local WindowServer[4811] <Error>: kCGErrorFailure: Set a breakpoint @ CGErrorBreakpoint() to catch errors as they are logged.
6/14/11 3:01:29 PM          com.apple.launchctl.Aqua[4842]          launchctl: Please convert the following to launchd: /etc/mach_init_per_user.d/com.adobe.versioncueCS3.monitor.plist
6/14/11 3:01:29 PM          com.apple.launchd.peruser.501[4840]          (com.apple.ReportCrash) Falling back to default Mach exception handler. Could not find: com.apple.ReportCrash.Self
6/14/11 3:01:29 PM          com.apple.launchd.peruser.501[4840]          (com.apple.Kerberos.renew.plist[4856]) Exited with exit code: 1
6/14/11 3:01:31 PM          [0x0-0x118118].com.google.Chrome[4878]          [0614/150131:INFO:breakpad_mac.mm(89)] Breakpad disabled
6/14/11 3:01:31 PM          com.apple.launchd.peruser.501[4840]          (0x100402ce0.mach_init.VersionCueCS3monitor) Failed to check-in!
6/14/11 3:01:34 PM          HyperDock Helper[4884]          Error loading /Library/ScriptingAdditions/Adobe Unit Types.osax/Contents/MacOS/Adobe Unit Types:  dlopen(/Library/ScriptingAdditions/Adobe Unit Types.osax/Contents/MacOS/Adobe Unit Types, 262): no suitable image found.  Did find:
        /Library/ScriptingAdditions/Adobe Unit Types.osax/Contents/MacOS/Adobe Unit Types: no matching architecture in universal wrapper
6/14/11 3:01:34 PM          [0x0-0x11f11f].de.bahoom.HyperDock-Helper[4884]          HyperDock Helper: OpenScripting.framework - scripting addition "/Library/ScriptingAdditions/Adobe Unit Types.osax" declares no loadable handlers.
6/14/11 3:01:43 PM          [0x0-0x117117].com.adiumX.adiumX[4877]          SocketRead err = -9806
6/14/11 3:01:43 PM          [0x0-0x117117].com.adiumX.adiumX[4877]          cdsa: SSLHandshake failed with error -9806 (connection closed via error)
6/14/11 3:01:50 PM          GrowlHelperApp[4872]          MailMe: No suitable SMTP account found

Answer 1

Doesn't sound like it.  It sounds like you're being logged-off.
Does your Mac go through the complete Restart cycle -- black screen, gray and/or blue screen momentarily, startup chime, etc? 
If you're not sure, do a Restart just to watch the process; the next time the problem occurs, see if it's the same.
You need to know which it is, as these will have very different causes, and different places to look for a solution.