Local MCX: Disabling automatic login also disables computer name setting

Hello all, I'm using local MCX to deploy on a bunch of new machines (using InstaDMG to build). I want to disable automatic login on all these machines and prevent the users from changing that setting. To do so, I created a computer group called LoginWindow, and then unchecked that ability in the Options tab of the Login Pref pane. Strangely though, when I do that, it also locks out the ability to change the computer name in System Preferences>Computer Name. Any idea what I could be doing to introduce this behavior? Any help would be greatly appreciated. Thanks, Jason