Stream content other than text/html to portlet


I want to create a report portlet, where a user will invoke an IS service which will generate a report (window word) content. I want to stream this content up to the portlet and display it in mime format application/msword.

For this I have extended the com.webmethods.caf.faces.portlet.FacesPortlet for the portlet and in the portlet.xml specified application/msword as a supported mime type.

Unfortunately when setting content type in the render method I get unsupported content-type when I try to set the content type of application/msword even though this is set to be supported.

Is there an error on my part, do I set the supported mime types on a global level, or is there other ways to accomplish this?