Have you checked whether you get the wsdl file? We got pretty much the same error:
ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[localhost].[/jmx-console].[HtmlAdaptor]] Servlet.service() for servlet HtmlAdaptor threw exception: java.lang.InstantiationException: com.ctc.wstx.io.WstxInputLocation
at java.lang.Class.newInstance0(Class.java:340) [:1.6.0_20]
...
and figured out (using wireshark) that the content length of the initial request to get the wsdl file was 0. It was turning us mad as we got the file using a browser but weren't able to get it programatically ...
Regards
M.