Further research leads me to believe that you are running JDK 6.0. Don't. Use 5.0 instead. JDK 6.0 comes with an implementation of SOAPMessage that spits out the error that you posted. JBossWS comes with its own implementation of SOAPMessage which is not being used because the one from the JDK takes precedence. Run with a 1.5 JVM and you should be just fine. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4031148#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...