How does GDM configuration work?

Question

There are at least two ways to configure GDM I know of:

1. is the /etc/gdm/custom.conf file that can be either hand edited or edited throu GUI gdmsetup. Autologin and timed login are configured here.
2. are the gconf schemas under /apps/gdm/ Those can be edite with gconf-editor running either as root or as a normal user. I guess editing it as a casual user does not have any impact since GDM runs as root. Sound among other things can be turned off here.

Are there any other ways? GDM refuses to let me autologin (on a fresh Natty install) (it does not ask for password, it merely wants that I select myself as a user at the login screen even though I am the only user on this computer).

Other interesting thing is that even if I purge GDM, its settings (including the custom.conf) do not change. Therefore there seems no way to reset GDM's settings.

BTW: my custom.conf is as follows (drew is my user):

[daemon]
TimedLoginEnable=false
AutomaticLoginEnable=true
TimedLogin=drew
AutomaticLogin=drew
TimedLoginDelay=1
DefaultSession=gnome

Edit: Ha, maybe it is not a configuration issue after all but a bug: https://bugs.launchpad.net/ubuntu/+source/gdm/+bug/753707

Solution

I am not actually sure if there are other ways or not to configure GDM, but it seems my question was sparked with this bug: https://bugs.launchpad.net/ubuntu/+source/gdm/+bug/753707

If so, gdmsetup configures what there is to configure about GDM, GDM only does not take autologing into account if ecryptfs is used.