Add a "Logout" link to the Webconfig interface that will clear all session data.
(Firefox only!) It's very difficult to completely logout of Webconfig when all browser sessions aren't closed. Firefox caches the username/password client-side so if you bring up the Webconfig interface again to try and login as another user, Firefox skips the login screen and takes the user directly into Webconfig. Internet Explorer do not behave this way and will prompt the user for a username/password every time.
Dialog that comes up when the logout link is click on should be the usual "Are you sure you want to logout of Webconfig" with the "OK", "Cancel" buttons.
Unknown if this this client-side issue can be solved server-side.
