I guess the easiest way to find out if you are affected by this bug is, to install the x11-xserver-utils package and run 'xrandr -q' - normally this should list a proper mode - it doesn't in my case. You can also run 'sudo get-edid' from the read-edid package - if it fails, you'll likely hit this bug.
I forgot, you also need to disable this option for the user ('sudo -u gdm' will only deal with the gdm login screen):
gconftool-2 --type bool -s "/apps/ gnome_settings_ daemon/ xrandr/ turn_on_ external_ monitors_ at_startup" false
I guess the easiest way to find out if you are affected by this bug is, to install the x11-xserver-utils package and run 'xrandr -q' - normally this should list a proper mode - it doesn't in my case. You can also run 'sudo get-edid' from the read-edid package - if it fails, you'll likely hit this bug.