Comment 27 for bug 737891

I managed to get it kinda working. The flashing issue with the Samsung seemed to be in a stale monitors.xml file. Posting for reference:

Boot laptop separate, then remove ~/.config/monitors.xml and /etc/gnome-settings-daemon/xrandr/monitors.xml

Shutdown. Place laptop on Ultrabase. Boot, system comes up in cloned screens mode.

gnome-display-properties, disable cloned mode, set monitor screen resolution, apply. We are now in dual head mode, with the unity launcher on the laptop screen. The only way to get it on the main screen seems to be to disable laptop screen.

disable laptop screen, apply. The confirmation countdown apparently runs somewhere else and will revert your change in 30 seconds... unless you press apply again and confirm it.

I still have to experiment on how I can make that setup stick... or work with the laptop lid closed on the Ultrabase.