login sequence aborts and restarts occasionally

Hello! I just updated to Lucid, and I've been noticing a bug.

I have my computer set-up to login automatically. This seems to work: the login process works correctly, I can start some applications. The problem is that _sometimes_ (I'm 95% sure it doesn't happen every time) the process stops somewhere and I'm returned to GDM. I can then proceed to login manually, and the second time it seems to work.

I've only noticed this happening when I was in a hurry, and I was starting a few programs as soon as the panel became available. However, since I was always in a hurry when this happened, I can't remember exactly everything I did. I'm not sure if timing is involved, or if this a manifestation of bug #522692 or bug #516412.

Today I started the computer, and it started an automatic log-in. I started a couple of apps: a script that mounts some SSHFS shares, Amarok, and Firefox, and I _think_ I started a terminal, but I don't remember if I had time to type anything in it. Then I was dumped to GDM's login screen. I logged in, I ran "geany ~/.xsession-errors*", then opened FF and this bug report.

I noticed the following in .xsession-errors.old (which I assume corresponds to the crashed session):

************
(gnome-terminal:1803): Gtk-CRITICAL **: gtk_accel_map_unlock_path: assertion `entry != NULL && entry->lock_count > 0' failed
gnome-settings-daemon: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.0.
** Message: Got disconnected from the session message bus; retrying to reconnect every 10 seconds
gnome-session: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.0.
** Message: <info> disconnected by the session bus.

nautilus: Fatal IO error 104 (Connection reset by peer) on X server :0.0.
nm-applet: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.0.
polkit-gnome-authentication-agent-1: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.0.
gnome-screensaver: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.0.
gtk-window-decorator: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.0.
libnotify-Message: GetServerInformation call failed: Connection was disconnected before a reply was received
libnotify-Message: Error getting spec version

(Pidgin:1616): libnotify-CRITICAL **: notify_get_server_caps: assertion `proxy != NULL' failed
gdu-notification-daemon: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.0.
padevchooser: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.0.
firefox-bin: Fatal IO error 0 (Success) on X server :0.0.
The application 'Pidgin' lost its connection to the display :0.0;
most likely the X server was shut down or you killed/destroyed
the application.
Session management error: Could not open network socket
Session management error: Could not open network socket
DCOPClient::attachInternal. Attach failed Could not open network socket
Session management error: Could not open network socket
kbuildsycoca running...
DCOP Cleaning up dead connections.
QLayout "unnamed" added to QVBox "unnamed", which already has a layout
QLayout: Adding KToolBar/mainToolBar (child of QVBox/unnamed) to layout for PlaylistWindow/PlaylistWindow
QObject::connect: Incompatible sender/receiver arguments
 StarManager::ratingsColorsChanged() --> ContextBrowser::ratingOrScoreOrLabelsChanged(const QString&)
Amarok: [Loader] Starting amarokapp..
Amarok: [Loader] Don't run gdb, valgrind, etc. against this binary! Use amarokapp.
************

The line starting with “(gnome-terminal:1803)” is always there, even in “normal” sessions (some other bug somewhere), everything else I assume belongs to the crash. It's strange that Amarok _does_ work in this session, although I don't think I started it again. The lines from it appeared after I started Geany (in the .xs-e.old file); perhaps start-up delay caused it to connect to the new session. No idea if it's relevant to this bug, I just mentioned it in case it's helpful.

Backtrace:
0: /usr/bin/X (xorg_backtrace+0x28) [0x4a25d8]
1: /usr/bin/X (0x400000+0x652dd) [0x4652dd]
2: /lib/libpthread.so.0 (0x7f18dc377000+0xf920) [0x7f18dc386920]
3: /usr/bin/X (GrabMatchesSecond+0xf) [0x44814f]
4: /usr/bin/X (0x400000+0x3c92b) [0x43c92b]
5: /usr/bin/X (0x400000+0x3cfe3) [0x43cfe3]
6: /usr/bin/X (0x400000+0xdecbf) [0x4decbf]
7: /usr/bin/X (XkbHandleActions+0x1c4) [0x507504]
8: /usr/bin/X (AccessXFilterPressEvent+0x23b) [0x5007cb]
9: /usr/bin/X (mieqProcessDeviceEvent+0x1c1) [0x4a1a11]
10: /usr/bin/X (mieqProcessInputEvents+0xda) [0x4a1b2a]
11: /usr/bin/X (ProcessInputEvents+0x9) [0x46fa29]
12: /usr/bin/X (0x400000+0x308b3) [0x4308b3]
13: /usr/bin/X (0x400000+0x2613a) [0x42613a]
14: /lib/libc.so.6 (__libc_start_main+0xfd) [0x7f18db070c4d]
15: /usr/bin/X (0x400000+0x25ce9) [0x425ce9]

Caught signal 3 (Quit). Server aborting

ProblemType: Bug
Architecture: amd64
CurrentDmesg: [ 31.874483] ppdev: user-space parallel port driver
Date: Fri Mar 5 13:16:38 2010
DistroRelease: Ubuntu 10.04
DkmsStatus:
 nvidia-current, 195.36.03, 2.6.32-15-generic, x86_64: installed
 nvidia-current, 195.36.03, 2.6.32-14-generic, x86_64: installed
EcryptfsInUse: Yes
MachineType: System manufacturer P5Q-PRO
NonfreeKernelModules: nvidia
Package: xorg 1:7.5+1ubuntu11
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-15-generic root=/dev/sda1 ro
ProcEnviron:
 LANGUAGE=en_US.UTF-8
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.32-15.22-generic
SourcePackage: nvidia-graphics-drivers
Uname: Linux 2.6.32-15-generic x86_64
dmi.bios.date: 11/04/2008
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1501
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: P5Q-PRO
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1501:bd11/04/2008:svnSystemmanufacturer:pnP5Q-PRO:pvrSystemVersion:rvnASUSTeKComputerINC.:rnP5Q-PRO:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: P5Q-PRO
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer
system:
 distro: Ubuntu
 codename: lucidarchitecture: x86_64kernel: 2.6.32-15-generic