Random freezes on ubuntu GNOME 16.04.

[Marcos Nascimento]

After some updates, this problem started.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: xorg 1:7.7+13ubuntu3
ProcVersionSignature: Ubuntu 4.8.0-58.63~16.04.1-generic 4.8.17
Uname: Linux 4.8.0-58-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
Date: Tue Jul 25 21:02:35 2017
DistUpgraded: Fresh install
DistroCodename: xenial
DistroVariant: ubuntu
ExtraDebuggingInterest: No
GraphicsCard: NVIDIA Corporation NV40 [GeForce 6800 XT] [10de:0048] (rev a1) (prog-if 00 [VGA controller])
InstallationDate: Installed on 2017-07-09 (16 days ago)
InstallationMedia: Ubuntu-GNOME 16.04.2 LTS "Xenial Xerus" - Release amd64 (20170215)
MachineType: System manufacturer System Product Name
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.8.0-58-generic root=UUID=aff9cad4-3e7e-4a04-ad79-367d2e8edc1a ro quiet plymouth:debug=1 splash vt.handoff=7
Renderer: Software
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/08/2006
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0701
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: P5VDC-X
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.:bvr0701:bd11/08/2006:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnP5VDC-X:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer
version.compiz: compiz N/A
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.70-1~ubuntu16.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 12.0.6-0ubuntu0.16.04.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 12.0.6-0ubuntu0.16.04.1
version.xserver-xorg-core: xserver-xorg-core N/A
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati N/A
version.xserver-xorg-video-intel: xserver-xorg-video-intel N/A
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau N/A
xserver.bootTime: Mon Jul 24 13:54:17 2017
xserver.configfile: default
xserver.devices:
 input Power Button KEYBOARD, id 6
 input Power Button KEYBOARD, id 7
 input Sleep Button KEYBOARD, id 8
 input Microsoft Basic Optical Mouse MOUSE, id 9
 input AT Translated Set 2 keyboard KEYBOARD, id 10
xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.18.4-1ubuntu6.1~16.04.1