How to define multiple xorg screens using the same device?

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http://askubuntu.com – I have a video-adapter(Dell MMH11) that is connected to the display-port of my graphics card. The adapter identifies itself to the graphics card as a 3840x1200 display. The adapter has two monitors connected to it (monitor resolution=1920x1200). A third monitor is connected directly on the graphics card DVI port(same resolution). So I have 3 monitors, but xorg only recognizes 2 "monitors" {adapter(3840*1200), samsung(1920x1200)}. I have these two "monitors" configured in xorg.conf with the nvidia driver and using Xanorama. The window manager (KDE in my case) runs just fine. However, the i (HowTos)