parameters don't appear in PDF when called with URI

[scottsyms]

Oh, great gurus of wisdom

I have a report developed in iReport that's displaying the parameter $P{officialagent}.  I put it up on JasperServer and passed it the parameter through the URI after turning off the prompting.

http://blahblah....../flow.html?......officialagent=Donald%20Rumsfeld...output=pdf

It renders happily, but the parameter doesn't display in the PDF.  It does if I choose doc, docx, excel, etc, but not with flash and PDF. 

I tried $P!{officialagent}, but no joy.

I suspect I'm missing something basic. I'm adding this to a gently maintained PHP/Python web app and would love to use iReports for our occasionally changing documents rather than craft PDF's generators by hand.  

Thanks for any help.

Scott

Halifax, Nova Scotia