Comment 31 for bug 737891

> I am actually unable to run *any* resolution on my external monitor, if I disable my laptop LCD in gnome's monitor configuration utility.

This is what I am seeing as well, in bug 767319(which is marked as duplicate, though slightly different than this bug's description).

https://bugs.launchpad.net/bugs/767319

This bug is critical for anyone docking a laptop or solely using an external monitor.