Tela parcialmente desfocada

Question

Estou usando o Ubuntu 12.04 e minha tela às vezes está borrada como na foto.

Às vezes, ele desaparece após o reinício e, às vezes, aparece novamente.

Você sabe qual é a causa desse problema e como corrigi-lo?

Uma foto novamente (o padrão muda)

$ lspci -nnk
00:00.0 Host bridge [0600]: Intel Corporation 82852/82855 GM/GME/PM/GMV Processor to I/O Controller [8086:3580] (rev 02)
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel driver in use: agpgart-intel
00:00.1 System peripheral [0880]: Intel Corporation 82852/82855 GM/GME/PM/GMV Processor to I/O Controller [8086:3584] (rev 02)
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
00:00.3 System peripheral [0880]: Intel Corporation 82852/82855 GM/GME/PM/GMV Processor to I/O Controller [8086:3585] (rev 02)
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
00:01.0 PCI bridge [0604]: Intel Corporation 82852/82855 GM/GME/PM/GMV Processor to AGP Controller [8086:3581] (rev 02)
    Kernel modules: shpchp
00:1d.0 USB controller [0c03]: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #1 [8086:24c2] (rev 03)
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel driver in use: uhci_hcd
00:1d.1 USB controller [0c03]: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #2 [8086:24c4] (rev 03)
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel driver in use: uhci_hcd
00:1d.2 USB controller [0c03]: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #3 [8086:24c7] (rev 03)
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel driver in use: uhci_hcd
00:1d.7 USB controller [0c03]: Intel Corporation 82801DB/DBM (ICH4/ICH4-M) USB2 EHCI Controller [8086:24cd] (rev 03)
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel driver in use: ehci_hcd
00:1e.0 PCI bridge [0604]: Intel Corporation 82801 Mobile PCI Bridge [8086:2448] (rev 83)
    Kernel modules: shpchp
00:1f.0 ISA bridge [0601]: Intel Corporation 82801DBM (ICH4-M) LPC Interface Bridge [8086:24cc] (rev 03)
    Kernel modules: iTCO_wdt, intel-rng
00:1f.1 IDE interface [0101]: Intel Corporation 82801DBM (ICH4-M) IDE Controller [8086:24ca] (rev 03)
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel driver in use: ata_piix
00:1f.3 SMBus [0c05]: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) SMBus Controller [8086:24c3] (rev 03)
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel modules: i2c-i801
00:1f.5 Multimedia audio controller [0401]: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) AC'97 Audio Controller [8086:24c5] (rev 03)
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel driver in use: snd_intel8x0
    Kernel modules: snd-intel8x0
00:1f.6 Modem [0703]: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) AC'97 Modem Controller [8086:24c6] (rev 03)
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel modules: snd-intel8x0m
01:00.0 VGA compatible controller [0300]: Advanced Micro Devices [AMD] nee ATI RV350 [Mobility Radeon 9600 M10] [1002:4e50]
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel driver in use: radeon
    Kernel modules: radeon, radeonfb
02:02.0 Ethernet controller [0200]: Broadcom Corporation BCM4401 100Base-T [14e4:4401] (rev 01)
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel driver in use: b44
    Kernel modules: b44
02:04.0 Network controller [0280]: Intel Corporation PRO/Wireless 2200BG [Calexico2] Network Connection [8086:4220] (rev 05)
    Subsystem: Intel Corporation Device [8086:2701]
    Kernel driver in use: ipw2200
    Kernel modules: ipw2200
02:06.0 CardBus bridge [0607]: Texas Instruments PCIxx21/x515 Cardbus Controller [104c:8031]
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel driver in use: yenta_cardbus
    Kernel modules: yenta_socket
02:06.2 FireWire (IEEE 1394) [0c00]: Texas Instruments OHCI Compliant IEEE 1394 Host Controller [104c:8032]
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel driver in use: firewire_ohci
    Kernel modules: firewire-ohci
02:06.3 Mass storage controller [0180]: Texas Instruments PCIxx21 Integrated FlashMedia Controller [104c:8033]
    Subsystem: Acer Incorporated [ALI] Device [1025:0064]
    Kernel driver in use: tifm_7xx1
    Kernel modules: tifm_7xx1
$ sudo dpkg -l '*mesa*'
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                              Version                           Description
+++-=================================-=================================-==================================================================================
ii  libgl1-mesa-dev                   8.0.4-0ubuntu0.6                  free implementation of the OpenGL API -- GLX development files
un  libgl1-mesa-dev-lts-quantal       <none>                            (no description available)
un  libgl1-mesa-dev-lts-raring        <none>                            (no description available)
ii  libgl1-mesa-dri                   8.0.4-0ubuntu0.4                  free implementation of the OpenGL API -- DRI modules
un  libgl1-mesa-dri-dev               <none>                            (no description available)
un  libgl1-mesa-dri-experimental      <none>                            (no description available)
ii  libgl1-mesa-glx                   8.0.4-0ubuntu0.6                  free implementation of the OpenGL API -- GLX runtime
un  libgl1-mesa-glx-lts-quantal       <none>                            (no description available)
un  libgl1-mesa-glx-lts-raring        <none>                            (no description available)
un  libgl1-mesa-glx-no-multiarch      <none>                            (no description available)
un  libgl1-mesa-swx11-dev             <none>                            (no description available)
ii  libglapi-mesa                     8.0.4-0ubuntu0.6                  free implementation of the GL API -- shared library
ii  libglu1-mesa                      8.0.4-0ubuntu0.6                  Mesa OpenGL utility library (GLU)
ii  libglu1-mesa-dev                  8.0.4-0ubuntu0.6                  Mesa OpenGL utility library -- development files
ii  mesa-common-dev                   8.0.4-0ubuntu0.6                  Developer documentation for Mesa
un  mesa-common-dev-lts-quantal       <none>                            (no description available)
un  mesa-common-dev-lts-raring        <none>                            (no description available)
un  mesa-glide2-dev                   <none>                            (no description available)
ii  mesa-utils                        8.0.1+git20110129+d8f7d6b-0ubuntu Miscellaneous Mesa GL utilities
un  mesag-dev                         <none>                            (no description available)
un  mesag3                            <none>                            (no description available)
un  mesag3+ggi-dev                    <none>                            (no description available)
un  xlibmesa-dev                      <none>                            (no description available)
un  xlibmesa-dri                      <none>                            (no description available)
un  xlibmesa-gl-dev                   <none>                            (no description available)
un  xlibmesa-glu-dev                  <none>                            (no description available)
un  xlibmesa3                         <none>                            (no description available)
un  xlibosmesa-dev                    <none>                            (no description available)