Description of problem:
I am not sure with the component, please reassign if I am wrong.
I am using laptop (Lenovo T500) and external display. Usualy I have the lid closed and using external display only and therefore I have the screen mirroring on. Occasionally my system starts with dual display anyway, I can't see the login dialog in gdm since it is on the "closed" display and the external display shows only background. If I open the lid the mirroring is restored and can see the dialog also on the external display.
Version-Release number of selected component (if applicable):
Hard to reproduce, the bug appears in less then 5% of boots.
Steps to Reproduce:
1. plug external display to your laptop
2. configure screen mirroring in gnome-display-settings
3. start your system with the lid closed
Sometimes the dual display is on, login dialog is only on the "closed" display.
Displays are mirrored properly.
Not _really_ a dupe, but close enough and probably fixed by the same plan as I have for the other bug.
*** This bug has been marked as a duplicate of bug 601319 ***