Setting mime type or content type in portlet

[Josh Holding <jh...@voyagerlearning.com>]

I'm in the process of moving some jsp's over into Jetspeed 1.4b4 portlets.
I've run into an issue where the jsp does the following:

response.setContentType( "application/vnd.ms-excel" );

This opens the generated html into Excel instead of the browser as expected
in a non-jetspeed environment, but not in Jetspeed.

I've tried doing something like this in the jsp:

rundata.setContentType( "application/vnd.ms-excel" );

but this does not work either.  I've also tried creating a new media-type in
media.xreg:

  <media-type-entry name="excel">
    <mime-type>application/vnd.ms-excel</mime-type>
    <meta-info>
      <title>Excel</title>
      <description>Excel mime type</description>
    </meta-info>
  </media-type-entry>

Then reference that in the portlet definition like so:

<media-type ref="excel"/>

This doesn't work either.  I wasn't sure what else to try and wanted to see
if anyone had any advice.  

Thanks-
Josh