Is this possible?

I've followed some guide to change to the radeon HD driver but compizcheck gives me this:

Distribution: Ubuntu 10.04
Desktop environment: KDE4
Graphics chip: ATI Technologies Inc RV770 [Radeon HD 4850]
Driver in use: radeonhd
Rendering method: None


Xorg.conf looks like this:

Section "Screen"
Identifier "Default Screen"
DefaultDepth 24
EndSection

Section "Module"
Load "glx"
EndSection

Section "Device"
Identifier "Default Device"
Driver "radeonhd"
option "DRI" "on" #this is the default in recent radeonhd versions
Option "AccelMethod" "EXA" #this is the default in recent radeonhd versions

EndSection

Section "Extensions"
Option "Composite" "Enable"
EndSection


I'm running Kubuntu 10.04.

Any ideas?