actually Jboss itself doesn't use port 8080, the tomacat uses this you can change the port settings in the
tomcat config file. even i m doing that and using port 8282.
and if really its a TNSListener who is using the port 8080, i think which would not be the case, just delete the listener and create a new customize one via oracle 9i network config assistance.
i think apache server, which is installed with oracle server, uses the port 8080 not the TNSListener.