I finally got around to hooking up a second monitor to my Ubuntu/Breezy laptop and convinced xorg.conf to ‘do the right thing’.
The compaq nc6000 notebook has the “ATI Technologies, Inc. Radeon Mobility 9600/9700 M10/M11 (RV350 NP)” video card
and has a video out at the back.
Here is my /etc/X11/xorg.conf with Xinerama (move windows from one screen to another). The aging Compaq monitor sits to the left of the nc6000 laptop.
Here is a copy of my configuration: xorg.conf-dual-head-xinerama