i own a DELL Latitude D610 laptop and I recently connected an external monitor. I googled and I figured out how to use xrandr and that if I set it up and reboot it, it will "lose" the settings. So, I added the command: xrandr --output VGA1 --auto --left-of LVDS1
in the Application Autostart (under Session and StartUp manager).
Now it almost works. When I reboot, the VGA1 is cloned in the login screen and after I log in it turns black, untill i press "windows key + P" to configure the display settings to "Both displays cloned".
After that is works like a charm!
It's not that a trouble to just configure this every time I log in, but for the knowledge of it I wanna know how to automate this even more.