Have you tried to set an IP address to the property java.rmi.server.hostname ?
E.g., starting JBoss as follows,
java -Djava.rmi.server.hostname=x.x.x.x ...
This works fine for a simple JBoss application. We can connect to the JBoss application remotely.
However, I wonder if this is a right solution since some JBoss application gets another error at its deployment time which we are still investigating.
Hoping this might help.