JBoss 6 run on localhost:8080

Webservice call by jboss ejb url http://locahost:9090/webservice/HelloService?wsdl

The code in EJB to build webservice port is:

URL wsdlUrl = new("http://locahost:9090/webservice/HelloService?wsdl);

Service service = Service.create(wsdlUrl,serviceName);

HelloServicePortType helloPort = service.getPort(HelloServicePortType.class);

at the first time call the helloPort generate correct, it use http://locahost:9090/webservice/HelloService?wsdl as wsdl location

then every call after first time call the wsdl location auto change to http://locahost:8080/webservice/HelloService?wsdl.

The code run on JBoss 5 fine, when migrate to JBoss 6, the problem happen.

Is this a JBoss 6 bug?