Comment 100 for bug 1292398

Not sure if this is equivalent, as I run unity-settings-daemon instead of gnome-settings-daemon (with the Compiz Unity-plugin turned off and gnome-panel instead), but it seems similar enough.

Just upgraded from 14.04 to 16.04.1.

I drop my laptop on a dock with two vertically oriented (rotated to portrait) monitors. This was working fine before, now it lights them up without the rotation. Rotating them manually via System Settings -> Displays, undocking and docking again reverts to the wrong (landscape) orientation.

The ~/.config/monitors.xml looks fine but seems to be ignored.
Reloading the settings with

  killall unity-settings-daemon

gives me the correct orientation, which is read from the monitor.xml (editing the file by hand and killing u-s-d accepts whatever changes I make), it just doesn't get triggered on docking changes.

That's the workaround for now: kill u-s-d every time I dock to that workplace, which may help with g-s-d too.
It would be nice for patchlvl 1 LTS upgrades to not break such basic stuff.