Comment 10 for bug 569879

Having the same problem ...

The following happens:
1) Log in - compositing has been disabled (and cannot be re-enabled if I
   remember correctly)
2) Then log out - display freezes (black screen/displaying terminal content/...).
   The system can still be rebooted using SysRq combinations/executing
   "sleep 300; sudo shutdown -r now" in a terminal before triggering the crash/...
3) Reboot and log in again - one plasma panel is corrupted (see screenshot), the
   other one looks as if compositing was disabled (according to the settings it is
   enabled though); after toggling compositing, the panel is displayed correctly

Backtrace of one crash (diff of kdm.log before logging out and before
rebooting, i.e. after the crash):

(EE) intel(0): Couldn't create pixmap for fbcon
(EE) intel(0): Couldn't create pixmap for fbcon
QFont::fromString: Invalid description 'Serif,20,5,0,50,0'
QFont::fromString: Invalid description 'Sans Serif,10,5,0,50,0'
QFont::fromString: Invalid description 'Sans Serif,10,5,0,75,0'
QInotifyFileSystemWatcherEngine::addPaths: inotify_add_watch failed: No such file or directory
QFileSystemWatcher: failed to add paths: /tmp/1446371504/.config/ibus/bus
Bus::open: Can not get ibus-daemon's address.
IBusInputContext::createInputContext: no connection to ibus-daemon
*** glibc detected *** /usr/bin/X: double free or corruption (fasttop): 0x0a2f4630 ***
======= Backtrace: =========
/lib/tls/i686/cmov/libc.so.6(+0x6b591)[0x17b591]
/lib/tls/i686/cmov/libc.so.6(+0x6cde8)[0x17cde8]
/lib/tls/i686/cmov/libc.so.6(cfree+0x6d)[0x17fecd]
/usr/bin/X(Xfree+0x21)[0x80a9f71]
/usr/bin/X(dixFreePrivates+0xaa)[0x808ce9a]
/usr/bin/X[0x8066e24]
/lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xe6)[0x126bd6]
/usr/bin/X[0x8066961]
======= Memory map: ========
[...]

Desktop environment: KDE 4.4.3

$ lsb_release -d
Description: Ubuntu 10.04 LTS

$ lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GME Express Integrated Graphics Controller (rev 03)

$ apt-cache policy xserver-xorg-video-intel
xserver-xorg-video-intel:
  Installed: 2:2.9.1-3ubuntu5
[...]