Binary package hint: xorg
I've seen this problem in this PC for years. Many times Linux works normally, without problems. Every now and then, depending on the programs I open, Ubuntu (and other Linuxes I tested) switches into a "graphic corruption mode": some screen elements are not drawn correctly.
For instance, while navigating with Firefox, after scrolling down on a webpage, only the lower part of the screen scrolls down, the rest remains as it is. If you hover the mouse cursor over links or tries to select text, then appears in the screen some text that was not shown without selecting. In other words, the webpage scrolls down, but the display is not updated correctly unless you select text. Unfortunately, I could not take a screenshot of Firefox with problems because the screen is updated and no more error is shown, neither in screen nor in screenshot.
The worst problem seems to be Emacs, screenshot attached. The white background is not shown, in its place is shown whatever was shown before selecting the Emacs window, like the desktop or other window's contents. Most of the times the "graphic corruption mode" is switched on is because I started Emacs, but not only Emacs causes this. On other distributions I got that problem very often using yakuake (IIRC it was Gentoo).
If I switch to terminal (Ctrl + Alt + F1) and change back to desktop, the "graphic corruption mode" is switched off, and screen mostly show the correct elements, except for some black or white lines that are shown occasionally.
To make the situation even worse, sometimes, instead of entering "graphic corruption mode", the computer freezes. Only the mouse cursor still moves, nothing else. The programs continue running after the freeze (I can tell you that for sure) but without input and output all that is left for me to do in that situation is a hard reset.
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 i686
Architecture: i386
CurrentDmesg:
[ 22.086128] CPUFREQ: Per core ondemand sysfs interface is deprecated - up_threshold
[ 23.682007] Marking TSC unstable due to cpufreq changes
[ 23.682839] Switching to clocksource acpi_pm
[ 26.980028] eth1: no IPv6 routers present
Date: Wed Jul 14 17:58:44 2010
DkmsStatus: Error: [Errno 2] Arquivo ou diretório não encontrado
GdmLog:
Error: command ['kdesudo', '--', 'cat', '/var/log/gdm/:0.log'] failed with exit code 1: QInotifyFileSystemWatcherEngine::addPaths: inotify_add_watch failed: No such file or directory
QFileSystemWatcher: failed to add paths: /home/gugamilare/.config/ibus/bus
Bus::open: Can not get ibus-daemon's address.
IBusInputContext::createInputContext: no connection to ibus-daemon
cat: /var/log/gdm/:0.log: No such file or directory
GdmLog1: Error: command ['kdesudo', '--', 'cat', '/var/log/gdm/:0.log.1'] failed with exit code 1: cat: /var/log/gdm/:0.log.1: No such file or directory
GdmLog2: Error: command ['kdesudo', '--', 'cat', '/var/log/gdm/:0.log.2'] failed with exit code 1: cat: /var/log/gdm/:0.log.2: No such file or directory
InstallationMedia: Kubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100427)
Lsusb:
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: PCCHIPS M871G
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-23-generic root=UUID=aa7cf55c-3c84-4342-b826-45227699083f ro quiet splash
ProcEnviron:
LANGUAGE=pt_BR:pt:en
PATH=(custom, user)
LANG=pt_BR.UTF-8
SHELL=/bin/bash
SourcePackage: xorg
dmi.bios.date: 09/15/2005
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 080011
dmi.board.name: M871G
dmi.board.vendor: PCCHIPS
dmi.board.version: 1.0
dmi.chassis.asset.tag: 0123ABC
dmi.chassis.type: 3
dmi.chassis.vendor: PCCHIPS
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr080011:bd09/15/2005:svnPCCHIPS:pnM871G:pvr1.0:rvnPCCHIPS:rnM871G:rvr1.0:cvnPCCHIPS:ct3:cvr1.0:
dmi.product.name: M871G
dmi.product.version: 1.0
dmi.sys.vendor: PCCHIPS
glxinfo: Error: [Errno 2] Arquivo ou diretório não encontrado
system:
distro: Ubuntu
codename: lucid
architecture: i686
kernel: 2.6.32-23-generic
Sorry, attached same image by mistake in the previous comment.
This screen I got after resizing Emacs' window horizontally, shrinking and enlarging afterwards.