"Default" session in LDM not logging in, only gnome-session works

[Jeremy Visser]

I'm having the same issue as this guy, who didn't get any replies to his
issue:

https://lists.ubuntu.com/archives/edubuntu-devel/2007-November/002442.html

If I log in with LDM, and I don't select a session to log in with (or
select the Default session in the selector), after I enter my
username/password, the screen goes blank (indicating this is not an SSH
problem), and after about 5 seconds, dumps me back to the LDM login
screen.

If I select "gnome-session" from the selector, GNOME logs in fine.
(Actually, it throws an error about gnome-settings-daemon not coming up,
requiring me to run it manually after login, but I think that's a
different issue.)

Where can I change what the "Default" session points to? Obviously, it
points to something non-existant, so if I could somehow get it to point
to gnome-session, that would fix it.

Thanks,
Jeremy.