802.1x authentication at login not working (com.apple.loginwindow.plist)

Question

We have a number of OSX Macs (10.4.11) in an 802.1x test environment.
All the Macs have been bound directly to a Windows 2003 Active Directory using the Directory Access Utility.
All the clients have been imaged from the same original OSX 10.4.3 image and upgraded to 10.4.11.
We would like the clients to Wirelessly 802.1x authenticate at user login.
Apple provide a useful How-to doc for this purpose:
http://docs.info.apple.com/article.html?artnum=303471
Great! Well, yes for some systems but not for others. We have two clients running that will not take the above procedure from Apple.
On the working clients the following file has been modified by the procedure above:
\library\Prefrences\com.apple.loginwindow.plist
On the non-working clients this file does not change.
I assume this may be a permissions issue but just can't figure it out. Any help, advice or pointers would be greatly appreciated.

Answer 1

I still don't know why Internet Connection is not updating com.apple.loginwindow. However, these articles have been helpful:
http://ninjamonkey.us/wordpress/index.php/2008/01/16/macos-x-login-with-8021x/
and
http://ninjamonkey.us/wordpress/index.php/2008/03/16/update-macos-x-login-with-8 021x/