Desktop effects not working anymore

[Ferdinand Smit <ferdinand@telegraafnet.nl>]

Hi,

Since i have upgraded my xserver to 1:7.4+3 my desktop effects do not work 
anymore. I still can use XRender but not OpenGL mode.

Popup message:

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.

Is this a known problem or do i have an error in my config?

Packages:
xserver-xorg   1:7.4+3
xserver-xorg-video-intel   2:2.8.0-2
ibgl1-mesa-dri   7.5-3
libgl1-mesa-glx    7.5-3
libglu1-mesa  7.5-3
libqt4-opengl   4:4.5.2-1
kdebase   4:4.2.4-1
... and the rest of kde-full

Video:
00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 
Integrated Graphics Controller (rev 0c)
00:02.1 Display controller: Intel Corporation Mobile GM965/GL960 Integrated 
Graphics Controller (rev 0c)

Xorg conf is a setup for two monitors, using AccelMethod UXA with Tiling 
disabled and Composite enabled. In de log it says that composite is enabled.

Regards,
Ferdinand