Comment 12 for bug 749817

I don't have an option in gdm for a guest session. When I logged in to a test account with little history, I get similar behaviour: it did actually come up at first with only the internal monitor working. Through the monitor control panel I could see the external monitor. It thought it was in side-by-side mode, but the external monitor was just black. When I tried turning off the internal screen, I was stuck with them both black. I tried waiting for a while to see if the "do you really want to keep this" kicked in, but it didn't bring the display back.

Again I could switch to vt1 and I got two samples of the intel registers.