I've just install ATI driver 8.30.3 and it works fine on my laptop (Radeon X300 video card).
Then, i've configured xinerama in order to plug an external display on my laptop but it seems that xinerama disactivates 3D accelation...

Here is the output of /var/log/Xorg.0.log

(II) fglrx(0): Xinerama extension enabled, disabling direct rendering.

Does ATI driver supports both xinerama and 3D acceleration ?

Thanks in advance