Spontaneously Logging Out?

Question

Anyone else seeing this?
My MacBook Pro is occasionally bailing out of the active user session.
I usually detect this by returning to the idle machine and finding it at the login window, with whatever account happened to be active (I usually have two accounts running) logged out. I have once seen it happen out of the corner of my eye: the screen abruptly switches to the login window. I generally don't leave any documents unsaved, but I have to assume that any such work would be lost if I left it that way.
There are no CrashReporter logs in my console. system.log seems to show the following message around the time of some of the events (but not all):
Mar 15 17:27:20 Dougs-MacBook-Pro kernel[0]: (94: coreservicesd)tfp: failed on 0:
Mar 15 17:27:23 Dougs-MacBook-Pro /System/Library/CoreServices/loginwindow.app/Contents/MacOS/loginwindow: Login Window Application Started
I did a Disk Repair and Repair Permissions last night, and it's still happening.
Any ideas?
TIA,
Doug K;
MacBook Pro, 1.83 GHz   Mac OS X (10.4.5)   1 Gig of RAMon one DIMM (BTO option)

Answer 1

My MacBook just logged me out, spontaneously, on wake from sleep. My "Log out after xxx minutes of inactivity" option was not checked.
Apr 6 23:50:53 Powerbook-2 kernel[0]: hibernatewriteimage done(0)
Apr 6 23:50:53 Powerbook-2 kernel[0]: sleep
Apr 6 23:50:53 Powerbook-2 kernel[0]: Enabling XMM register save/restore and SSE/SSE2 opcodes
Apr 6 23:50:53 Powerbook-2 kernel[0]: Started CPU 01
Apr 6 23:50:53 Powerbook-2 kernel[0]: System Wake
Apr 6 23:50:54 Powerbook-2 kernel[0]: USB caused wake event (EHCI)
Apr 6 23:50:55 Powerbook-2 mDNSResponder: mDNSPlatformRawTime went backwards by 191 ticks; setting correction factor to 1386845432
Apr 6 23:50:56 Powerbook-2 lookupd[518]: lookupd (version 369.5) starting - Thu Apr 6 23:50:56 2006
Apr 6 23:50:56 Powerbook-2 crashdump[517]: WindowServer crashed
Apr 6 23:50:56 Powerbook-2 configd[37]: rtmsg: error writing to routing socket
Apr 6 23:50:56 Powerbook-2 loginwindow[136]: LWScreenLock: reactivate hotkeys, cgerror = -308
Apr 6 23:50:56 Powerbook-2 /System/Library/PrivateFrameworks/Apple80211.framework/Resources/airport: Error: owner of process not logged in on console - exiting.
Apr 6 23:50:56 Powerbook-2 /System/Library/CoreServices/loginwindow.app/Contents/MacOS/loginwindow: Login Window Application Started
Apr 6 23:50:58 Powerbook-2 crashdump[517]: crash report written to: /Library/Logs/CrashReporter/WindowServer.crash.log
Apr 6 23:50:58 Powerbook-2 /Library/StartupItems/iScroll2/iScroll2Daemon: No console user currently logged in.\n
Apr 6 23:50:59 Powerbook-2 /Library/StartupItems/iScroll2/iScroll2Daemon: Default settings found; 20 settings loaded.\n
Apr 6 23:50:59 Powerbook-2 loginwindow[520]: Login Window Started Security Agent
Apr 6 23:50:59 Powerbook-2 kernel[0]: (63: coreservicesd)tfp: failed on 0:
MBP 2.0, G5 2x2.0, Cube, Mini (2), Intel Mini   Mac OS X (10.4.6)