OK, more information.

I have found that when my validation works, it is using the code from the JDK 1.7, but I think that when running within JBOSS it is using validation-api-1.0.0.GA-redhat-2.jar which has it's own implementation, and which is causing the exception.

I have tracked down that the issue resides with the Validator and what source it uses to validate.

If I retrieve an Element from the SOAP Message and use the following code:

        DOMSource domSource = new DOMSource(requestElt);

        validator.validate(domSource);

This fails in JBOSS but works with JDK 1.7

If I use

     validator.validate(new StreamSource(new StringReader(getElementContent(requestElt))));

where

    public static String getElementContent(Element message)
            throws SOAPException, IOException {

        Document document = message.getOwnerDocument();
        DOMImplementationLS domImplLS = (DOMImplementationLS) document
                .getImplementation();
        LSSerializer serializer = domImplLS.createLSSerializer();
        return serializer.writeToString(message);
    }

This works both with JBOSS and JDK 1.7

The issue appears to be that the SOAP Message is UTF-16 rather than UTF-8

SO I have a solution that works, but has more lines of code to get there in both Oracle and JBOSS