We already have a custom JAAS module installed at the AS level (4.0.5). Would this module interfere in any way with the JAAS module of the portal?
It would appear that something that I was trying to do in replacing the login page had prevented the custom LoginModule that I had developed from getting activated (it may nave been the <security-constraints> in the web.xml file of the portal-server.war file). I backed up my portal .sar directory in which I had made the changes, put a fresh installation (a "clean" .sar directory from the installation download), and then modified the jboss-portal.sar/conf/login-config.xml file again to point at my custom LoginModule. I then placed my custom implementation .jar file underneath the /jboss-portal.sar/lib directory, and then I began to see my custom messages from the LoginModule getting output to the log.