Comment 12 for bug 1545834

Finally, I made some progress, hope it helps you.

I've checked the daily image, this is what I've found:
 * In the default config, there removal of default external monitor is handled correctly.
 * Then I arranged my displays as I use it every day (see attached image)
 * The unity-settings-daemon has crashed after disconnecting the external monitor (apport popped up, but I did not file a new bug).

So I thought that I have the same thing with 14.04 too, but maybe I have disabled reporting errors for settings-daemon earlier. I've found a file called ~/.apport-ignore.xml, and yes, it contained the settings daemon. I removed it from ignore and now I have crash file around the time of monitor removal, and its the crash of settings daemon.