Bug#585094: gnome-control-center: gnome-display-properties wrongly detects external monitor connected

[Martin Dimitrov]

Hi,

I had the same problem as you. I managed to solve it using the
guidelines form this post:
http://www.jejik.com/articles/2008/10/setting_up_dual_monitors_system-wide_with_xrandr_on_debian_lenny/

Regards,
Martin