Comment 77 for bug 1288572

Tim,

I removed all changes in /sbin/prime-offload. (removed the two xrandr lines I added manually)
I installed ubuntu-drivers-common 1:0.2.91.2~trusty3 as you asked in IRC.
This new package does not solve gdm and gnome-shell problems.
I found a workaround to solve gdm and gnome-shell issue by adding the following to /etc/X11/xorg.conf:

Section "Monitor"
    Identifier "VGA-0"
    Option "Ignore" "True"
EndSection

After the above modification/addition of xorg.conf, gdm and gnome-shell can be loaded successfully with nvidia-driver.