monitor shutdown causes GPU hang

[Sean Fitzpatrick]

Binary package hint: gnome-power-manager

I'm filing this under gnome-power-manager since the problem occurs when it attempts to put the monitor to sleep (but it might be an Xorg problem).
Problem: occasionally (about one time in three) when the system powers down the monitor after 30 minutes, the OS gets stuck in an infinite loop: Mouse on blank screen - flash of some boot message - Ubuntu login sound.

I was able to get into a virtual terminal with Ctrl+Alt+F2; there was an error message at the top of the screen about a GPU hang. (Unfortunately, I didn't write it down.) This is my parents' computer; I'm trying to troubleshoot while visiting. Previously they had just disabled putting the monitor to sleep as a workaround (and until then had been doing a hard reboot).

If there is further information I should post, please let me know.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: gnome-power-manager 2.30.0-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-31.61-generic 2.6.32.32+drm33.14
Uname: Linux 2.6.32-31-generic x86_64
Architecture: amd64
Date: Thu May 5 21:26:56 2011
ExecutablePath: /usr/bin/gnome-power-manager
GnomeSessionIdleInhibited: No
GnomeSessionInhibitors: None
GnomeSessionSuspendInhibited: No
InstallationMedia: Ubuntu 10.04.1 LTS "Lucid Lynx" - Release amd64 (20100816.1)
MachineType: Gigabyte Technology Co., Ltd. H55M-D2H
ProcCmdLine: BOOT_IMAGE=/vmlinuz-2.6.32-31-generic root=UUID=7413dbd6-38cc-42bc-b0cb-f196a65ea089 ro quiet splash
ProcEnviron:
 LANG=en_CA.utf8
 SHELL=/bin/bash
SourcePackage: gnome-power-manager
XsessionErrors: (polkit-gnome-authentication-agent-1:1466): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed
dmi.bios.date: 08/20/2010
dmi.bios.vendor: Award Software International, Inc.
dmi.bios.version: F3
dmi.board.name: H55M-S2H
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.modalias: dmi:bvnAwardSoftwareInternational,Inc.:bvrF3:bd08/20/2010:svnGigabyteTechnologyCo.,Ltd.:pnH55M-D2H:pvr:rvnGigabyteTechnologyCo.,Ltd.:rnH55M-S2H:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvr:
dmi.product.name: H55M-D2H
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

[Sean Fitzpatrick (sean-fitzpatrick)]

Here is the xsession-errors file.