blank screen after unlocking the screen

[mathieg2]

To reproduce this bug, I lock the screen. When I try to unlock the screen, the screen flashes up with the wallpaper - then back to black again. To workaround the problem, I have disabled the screen lock. To get my computer back today, I will kill the X process - or restart lightdm. standard - black screen - screensaver on ubuntu. I created this bug-report using ssh from another computer

This is probably the same bug as 943836. I'm going to have a play with gdb if I can work out how.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: xorg 1:7.6+10ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-18.28-generic-pae 3.2.9
Uname: Linux 3.2.0-18-generic-pae i686
NonfreeKernelModules: nvidia
.proc.driver.nvidia.gpus.0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/gpus/0'
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86 Kernel Module 295.20 Mon Feb 6 20:25:38 PST 2012
 GCC version: gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu2)
ApportVersion: 1.94-0ubuntu2
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,decor,vpswitch,commands,resize,compiztoolbox,grid,snap,place,regex,move,ring,obs,imgpng,gnomecompat,mousepoll,animation,session,wall,workarounds,expo,ezoom,unitymtgrabhandles,fade,scale,unityshell]
Date: Wed Mar 7 20:53:12 2012
DistUpgraded: Log time: 2012-02-26 19:57:58.778115
DistroCodename: precise
DistroVariant: ubuntu
EcryptfsInUse: Yes
ExtraDebuggingInterest: Yes, whatever it takes to get this fixed in Ubuntu
GpuHangFrequency: Several times a day
GpuHangReproducibility: Yes, I can easily reproduce it
GpuHangStarted: Immediately after installing this version of Ubuntu
GraphicsCard: NVIDIA Corporation G96 [GeForce 9400 GT] [10de:0641] (rev a1) (prog-if 00 [VGA controller])
JockeyStatus:
 xorg:nvidia_current - NVIDIA accelerated graphics driver (Proprietary, Enabled, In use)
 xorg:nvidia_current_updates - NVIDIA accelerated graphics driver (post-release updates) (Proprietary, Disabled, Not in use)
MachineType: System manufacturer System Product Name
ProcEnviron:
 TERM=screen-bce
 PATH=(custom, user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-18-generic-pae root=UUID=4a45f643-9353-4adc-b0a8-298b00ef039d ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
Title: Xorg freeze
UpgradeStatus: Upgraded to precise on 2012-02-26 (9 days ago)
dmi.bios.date: 11/16/2010
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1101
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: M4A87TD EVO
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.:bvr1101:bd11/16/2010:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnM4A87TDEVO:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer
version.compiz: compiz 1:0.9.7.0~bzr2995-0ubuntu5
version.libdrm2: libdrm2 2.4.30-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 8.0.1-0ubuntu2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 8.0.1-0ubuntu2
version.nvidia-graphics-drivers: nvidia-graphics-drivers N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.11.4-0ubuntu4
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.6.99.901+git20120126-0ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20111219.aacbd629-0ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.17.0-1ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20111201+b5534a1-1build2