mime type mtom requests

Issue

We have a SAAJ-based client or endpoint (perhaps using the Provider interface defined by JAX-WS) that creates a SOAPMessage. If I run it on JDK 1.6 or Tomcat, the code creates an HTTP request with this content-type:

multipart/related;type="application/xop+xml"

When I run the same code on JBoss EAP 5.1.2, the request has the following content-type:

multipart/related; type="text/xml"

The 3rd party server that hosts the webservice refuses the invocation from jboss because of the invalid content type of the requests. How do I fix this?