Xorg freeze on switch user - Ubuntu 10.04

[Hasse]

Binary package hint: xorg

Fresh install of Ubuntu 10.04 x86_64
Problem: Screen goes black, and keyboard does not respond. Not even to NumLock. top shows Xorg process is taking 99.9% of CPU resource.
Can SSH into machine.

To reproduce:
1. Log in as user1
2. Switch to user2
3. Log out user2, or switch to user1 (Same effect)

Have tried:
Uninstall gnome-screensaver - does not help (Worked when I had same symptoms after updating to 10.04 on the same machine/HW)
restart gdm through SSH - does not help
xgamma through SSH -. does not help

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: xorg 1:7.5+5ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-22.36-generic 2.6.32.11+drm33.2
Uname: Linux 2.6.32-22-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
Date: Fri Jun 18 13:04:09 2010
DkmsStatus:
 nvidia-173, 173.14.22, 2.6.32-21-generic, x86_64: installed
 nvidia-173, 173.14.22, 2.6.32-22-generic, x86_64: installed
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100429)
MachineType: To Be Filled By O.E.M. To Be Filled By O.E.M.
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-22-generic root=UUID=f83e7985-db81-43e0-8fa0-00ffaa9d8b7a ro quiet splash
ProcEnviron:
 LANG=en_IE.UTF-8
 SHELL=/bin/bash
SourcePackage: xorg
Symptom: display
Title: Xorg freeze
dmi.bios.date: 11/14/2005
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1017.002
dmi.board.name: A8V Deluxe
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.:bvr1017.002:bd11/14/2005:svnToBeFilledByO.E.M.:pnToBeFilledByO.E.M.:pvrToBeFilledByO.E.M.:rvnASUSTeKComputerInc.:rnA8VDeluxe:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: To Be Filled By O.E.M.
dmi.product.version: To Be Filled By O.E.M.
dmi.sys.vendor: To Be Filled By O.E.M.
system:
 distro: Ubuntu
 codename: lucid
 architecture: x86_64
 kernel: 2.6.32-22-generic

[Hasse (hans-kristian-moen)]

Update:
killing the Xorg process and then restarting gdm gets the system back up and running without a full reboot.

//hk

[dino99 (9d9)]

Closing that outdated report as EOL has been reached long time ago