Sean; Sorry, I did not see this comment until today. Well, I logged in fine so I think the problem lies not with Jboss or Alfresco.
However, I made a small change to my JBoss installation. The init script for starting it from /etc/rc.d/init.d was not picking up the value for $JAVA_HOME (although it had $JBOSS_HOME fine and I set both of those in /etc/profile.d/jboss.sh), so I just defined $JAVA_HOME in this init scrit again. I think this might have been causing JBoss to ponit to thr JRE instead of the JDK. I found out when I once started JBoss by running bin/run.sh manually on the console. I did this because on one occasion I had JBoss crash due to an apparent out of memory error and I went to investigate. I'm not sure that this helps or even solves the problem which may lie elsewhere. But so far Alfresco is working for me. Keep in mind that due to lack of time I haven't done any work on it except create users.