Comment 12 for bug 808677

I have tried with some other monitor. I was able to attach it and set separate resolution for the external monitor(not mirroring) . I had both notebook and external monitor(1280 x 1024 ) running. After that I selected "off" option in the display manager for the notebook's display to turn off it in order to use the external monitor as primary monitor with the unity panel. Both displays went black. The only way was to shut down and reboot.

I can't test it with the previous display (1920x1080). With that one everything hanged and went to black right after I plug in the external display and set it as separate screen.

With the current one the issue appears after I disable internal notebook's display to use the external display only.