Jboss 3.0.x usually uses jetty as its web server, and the default configuration of this service is to append the http server requests to the request.log file in the log directory.
Jboss 4.0.x now uses tomcat as its web server, and the default is not to append anything related to http requests. You have to change this behavior in the server.xml file in the $JBOSS_HOME/server/default/deploy/jbossweb-tomcat50.sar directory
At least... that worked for me
Hope this helps