graphics errors and random freezes of the whole system

[user722]

Windows leave pixel sized errors on the background when moved around. The whole system freezes when using for example firefox or file manager. Only way to recover from the freeze is to push the reset button.

The login screen is in 24 bit display mode but the user desktop is 16 bit after fresh install. I changed it to 24 bit by creating this file:

/etc/X11/xorg.conf:
Section "Screen"
 Identifier "Default Screen"
 DefaultDepth 24
EndSection

After this change there have been no graphics errors or freezes. Mouse pointer sometimes disappears for a few seconds. The nouveau driver still generates error messages in the system log.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: lubuntu-desktop 0.38
ProcVersionSignature: Ubuntu 3.2.0-31.50-generic 3.2.28
Uname: Linux 3.2.0-31-generic i686
ApportVersion: 2.0.1-0ubuntu13
Architecture: i386
Date: Fri Oct 12 14:17:18 2012
InstallationMedia: Lubuntu 12.04 "Precise Pangolin" - Release i386 (20120423.1)
ProcEnviron:
 LANGUAGE=en_GB:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: lubuntu-meta
UpgradeStatus: No upgrade log present (probably fresh install)