Attached to this email is the patch file that I mentioned  
previously.  This patch will allow you to select via the Captive  
Portal config screen to only allow one user per login ID.  Further  
logins will kick the previous user out... (Which should be a good  
enough reason to not share passwords, especially if you use VPN!)

This has been tested with local authentication.  I believe it will  
also work with Radius authentication, but haven't actually tested it  
in that environment.

Paul