[xubuntu-users] configure Radeon video card for two screens

[Wybo Dekker]

Hi, I have replaced my video card with an ATI Cedar PRO Radeon HD 5450
and attached two identical screens to it. I also installed fglrx. But my
two screens show the same image.
When I try to configure my display (Settings Manager -> Display) I see
two identical screens, DFP1 and DFP2, both with `Use this output'
checked on, but both screens show the same image.
When I compare ~/.config/xfce4/xfconf/xfce-perchannel-xml/displays.xml
with the one on another (working) two-screen computer, the latter has an
entry:
 <property name="MinimalAutoConfig" type="empty">
which is missing in the other machine.

What can I do to tell my machine that it has two screens and that it
should combine the two to one big screen?
(Window-7 works does so!)
-- 
Wybo