Xorg freeze without any reason but CTRL+ALT+LEFT (RIGHT) fix it

[hetman]

Binary package hint: xorg

My system runs fine but some time without any reason xorg freezes the mouse pointer moves, but delayed. No button response.
But if i press CTRL+ALT+LEFT (RIGHT) fix it (key previously pressed trigger).

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: xorg 1:7.5+5ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-23.37-generic 2.6.32.15+drm33.5
Uname: Linux 2.6.32-23-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
Date: Tue Jul 20 21:27:56 2010
DkmsStatus:
 virtualbox-ose, 3.1.6, 2.6.32-23-generic, x86_64: installed
 virtualbox-ose, 3.1.6, 2.6.32-22-generic, x86_64: installed
 nvidia-current, 195.36.24, 2.6.32-23-generic, x86_64: installed
 nvidia-current, 195.36.24, 2.6.32-22-generic, x86_64: installed
GdmLog2: X: /tmp/.X11-unix has suspicious mode (not 1777) or is not a directory, aborting.
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100429)
MachineType: Acer Aspire 5720Z
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-23-generic root=UUID=7a13c3a9-8f20-49c2-9d31-d6dd009637dd ro quiet splash
ProcEnviron:
 LANG=ru_RU.utf8
 SHELL=/bin/bash
SourcePackage: xorg
Symptom: display
Title: Xorg freeze
dmi.bios.date: 11/10/2008
dmi.bios.vendor: Acer
dmi.bios.version: V1.45
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Nettiling
dmi.board.vendor: Acer
dmi.board.version: V1.45
dmi.chassis.type: 1
dmi.chassis.vendor: Acer
dmi.chassis.version: V1.45
dmi.modalias: dmi:bvnAcer:bvrV1.45:bd11/10/2008:svnAcer:pnAspire5720Z:pvrV1.45:rvnAcer:rnNettiling:rvrV1.45:cvnAcer:ct1:cvrV1.45:
dmi.product.name: Aspire 5720Z
dmi.product.version: V1.45
dmi.sys.vendor: Acer
system:
 distro: Ubuntu
 codename: lucid
 architecture: x86_64
 kernel: 2.6.32-23-generic