Created attachment 89751 [details]
crlog1.txt

Kernel crash at ubuntu user logon or "startx".
There are also a lot of red spots and signs on the monitor, see bug on
launchpad.
https://bugs.launchpad.net/bugs/1085187

Kernel version: Linux version 3.7.0-rc8-custom+ (root@duex) (gcc version
4.7.2 (Ubuntu/Linaro 4.7.2-12ubuntu2) ) #1 SMP Sat Dec 8 18:00:39 CET 2012

See attached kernel log (crlog1.txt and crlog2.txt) output taken via
kdump mechanism

Environment: Ubuntu Raring Ringtail (development branch) - Release: 13.04

Software: See attached si_ver_linux.txt for the output of ver_linux script

Processor information: See attached si_cpuinfo.txt for /proc/cpuinfo

Module information: See attached si_proc_modules.txt for /proc/modules

Loaded driver and hardware information: See attached si_proc_ioports.txt
for /proc/ioports - See attached si_proc_iomem.txt for /proc/iomem

PCI information: See attached si_lspci.txt for lspci -vvv

SCSI information: See attached si_proc_scsi_scsi.txt for /proc/scsi/scsi

See attached si_ls_proc.txt for the output of "ls /proc"

Workaround:
Problems disappear when one of the following is applied
a) Using fglrx instead of radeon
b) Using "radeon.nomodeset=0" command line
c) Setting Option "NoAccel" "True" in xorg.conf