I don't think I'm doing this correctly! The plugin is registering new users ok, but this is the registration flow that i'm seeing (for a new user, currently logged-in to FB):
1) the login page recognizes the FB account and allows him to register
2) upon succcssful regsitration the account is successfully created BUT the user is directed back the same registration page /wp-login.php?action=register
... I don't get it. Is there some way that I can control what page loads after successfully registering a new user???