After upgrading to KDE 4.8, I get the follow error when trying to get the desktop effects that worked in my previous KDE version working again:
window effects error.png
Failed to activate desktop effects using the given configuration options. Settings will be reverted to their previous values.
Check your X configuration. You may also consider changing advanced options, especially changing the compositing type.
And these effects are disabled:
window effects error1.png
So, I added the following to my /etc/X11/xorg.conf:
Option "Composite" "Enable"
But that didn't help. I still get this message in my ~/.xsession-errors:
OpenGL vendor string: Tungsten Graphics, Inc
OpenGL renderer string: Mesa DRI Intel(R) Ironlake Mobile
OpenGL version string: 2.1 Mesa 7.9.2
OpenGL shading language version string: 1.20
GPU class: i965
OpenGL version: 2.1
GLSL version: 1.20
Mesa version: 7.9.2
X server version: 1.9.5
Linux kernel version: 3.2.2
Direct rendering: yes
Requires strict binding: yes
GLSL shaders: yes
Texture NPOT support: yes
kwin(2751): KWin requires at least Mesa 7.10 for OpenGL compositing.
kwin(2751): Failed to initialize compositing, compositing disabled
kwin(2751): Consult http://techbase.kde.org/Projects/KWin/4.0-release-notes#Setting_up
For some reason KWin thinks I have an older OpenGL version.
Interestingly, switching my compositing type from OpenGL to XRender is a small improvement, but many desktop effects still don't work.
Also, I get a KWin segmentation fault occasionally, too, which is related to this
Thanks for the help