Folks, you're setting wrong parameters in the message context, please have a look at the page I linked before, in particular section "Authentication and authorization" -> "Client".
The jbossws-cxf testsuite and binary distribution comes with example of this btw, see http://anonsvn.jboss.org/repos/jbossws/stack/cxf/tags/jbossws-cxf-4.1.0.Final/modules/testsuite/cxf-tests/src/test/java/org/jboss/test/ws/jaxws/samples/wsse/policy/basic/UsernameTestCase.java