WindowServer port death causes instant logout

Hi, I've just had my computer instant-logout twice now. Poking around, it seems to be a problem that's been noted on these forums before, the WindowServer crashing. Both times, the event happened when I was on YouTube; it does not happen consistently.

Any idea how to fix it? Has Apple said anything about this problem?

Incidentally, while the Console log claims that a crash report was written to the /DiagnosticReports folder, the folder is presently empty.

Thank you for your help.

12/25/10 10:09:27 PM WebKitPluginHost[7478] Warning once: This application, or a library it uses, is using NSQuickDrawView, which has been deprecated. Apps should cease use of QuickDraw and move to Quartz.
12/25/10 10:09:27 PM com.apple.WebKit.PluginAgent[3108] 2010-12-25 22:09:27.005 WebKitPluginHost[7478:903] Warning once: This application, or a library it uses, is using NSQuickDrawView, which has been deprecated. Apps should cease use of QuickDraw and move to Quartz.
12/25/10 10:09:55 PM Safari[3102] HIToolbox: received notification of WindowServer event port death.
12/25/10 10:09:55 PM Finder[1507] HIToolbox: received notification of WindowServer event port death.
12/25/10 10:09:55 PM Pages[1563] HIToolbox: received notification of WindowServer event port death.
12/25/10 10:09:55 PM Scrivener[2288] HIToolbox: received notification of WindowServer event port death.
12/25/10 10:09:55 PM Scrivener[2288] port matched the WindowServer port created in BindCGSToRunLoop
12/25/10 10:09:55 PM iTunes[7115] HIToolbox: received notification of WindowServer event port death.
12/25/10 10:09:55 PM SystemUIServer[1506] HIToolbox: received notification of WindowServer event port death.
12/25/10 10:09:55 PM com.apple.launchd.peruser.501[1501] (com.apple.Dock.agent[1505]) Exited with exit code: 1
12/25/10 10:09:56 PM WebKitPluginHost[7478] HIToolbox: received notification of WindowServer event port death.
12/25/10 10:09:56 PM com.apple.launchd[1] (com.apple.WindowServer[71]) Job appears to have crashed: Segmentation fault
12/25/10 10:09:56 PM imagent[1528] Unable to create APS daemon connection: (ipc/mig) server died
12/25/10 10:09:56 PM imagent[1528] Unable to set enabled topics: (ipc/send) invalid destination port
12/25/10 10:09:56 PM VMware Fusion Helper[1540] HIToolbox: received notification of WindowServer event port death.
12/25/10 10:09:56 PM VMware Fusion Helper[1540] port matched the WindowServer port created in BindCGSToRunLoop
12/25/10 10:09:58 PM com.apple.ReportCrash.Root[7972] 2010-12-25 22:09:58.971 ReportCrash[7972:2903] Saved crash report for WindowServer[71] version ??? (???) to /Library/Logs/DiagnosticReports/WindowServer 2010-12-25-220958localhost.crash
12/25/10 10:10:02 PM com.apple.WindowServer[7974] Sat Dec 25 22:10:02 xxx.local WindowServer[7974] <Error>: kCGErrorFailure: Set a breakpoint @ CGErrorBreakpoint() to catch errors as they are logged.
12/25/10 10:10:22 PM com.apple.launchd.peruser.501[1501] (com.apple.ReportCrash) Falling back to default Mach exception handler. Could not find: com.apple.ReportCrash.Self
12/25/10 10:10:28 PM com.apple.launchd.peruser.501[1501] (com.adobe.ARM.202f4087f2bbde52e3ac2df389f53a4f123223c9cc56a8fd83a6f7ae[8021]) posix_spawn("/Applications/Adobe Reader.app/Contents/MacOS/Updater/Adobe Reader Updater Helper.app/Contents/MacOS/Adobe Reader Updater Helper", ...): No such file or directory
12/25/10 10:10:28 PM com.apple.launchd.peruser.501[1501] (com.adobe.ARM.202f4087f2bbde52e3ac2df389f53a4f123223c9cc56a8fd83a6f7ae[8021]) Exited with exit code: 1
12/25/10 10:10:29 PM com.apple.launchd.peruser.501[1501] (com.apple.Kerberos.renew.plist[8015]) Exited with exit code: 1