I did a similar thing for my dual-monitor desktop. This is my xorg.conf:
Code:
Section "Device"
Identifier "Default Device"
Driver "radeon"
EndSection
Section "Monitor"
Identifier "DVI-0"
EndSection
Section "Monitor"
Identifier "DVI-1"
Option "RightOf" "DVI-0"
EndSection
Section "Screen"
Identifier "Default Screen"
SubSection "Display"
Virtual 2560 1024
EndSubSection
EndSectio
And if this issue is solved, mark the thread as solved.