When running the nvidia restricted driver I was unable to setup twinview.
The solution was to force the refresh of the second LCD.
Code:
Section "Screen"
Identifier "Screen0"
Device "Videocard0"
Monitor "Monitor0"
DefaultDepth 24
Option "TwinView" "1"
Option "TwinViewXineramaInfoOrder" "DFP-1"
Option "metamodes" "CRT: 1280x1024_60 +1280+0, DFP: nvidia-auto-select +0+0"
SubSection "Display"
Depth 24
EndSubSection
EndSection