SirPAC Internal error on Waterson's Mozilla example

Hi!
I attempted Chris Waterson's Mozilla example (from the "rdf:in fifty words or less" article, http://www.mozilla.org/rdf/50-words.html), with the following result:
Errors
Fatal Error: Reference must end with ';'. (line 5, column 95)Internal error java.lang.NullPointerException
The submitted code (the rdf:Description line is the offending line, allegedly...):
<?xml version="1.0"?>
<rdf:RDF
 xmlns:rdf="http://www.w3.org/TR/WD-rdf-syntax#"
 xmlns:sm="http://www.mozilla.org/smart-mail/schema#">
 <rdf:Description about="http://www.mozilla.org/smart-mail/get-mail.cgi?user=waterson&folder=inbox">
 <sm:message id="4025293">
 <sm:recipient>
 Chris Waterson "waterson@netscape.com"
 </sm:recipient>
 <sm:sender>
 Aunt Helga "helga@netcenter.net"
 </sm:sender>
 <sm:received-by>x-wing.mcom.com</sm:received-by>
 <sm:subject>Great recipe for Yam Soup!</sm:subject>
 <sm:body>
 http://www.mozilla.org/smart-mail/get-body.cgi?id=4025293
 </sm:body>
 </sm:message>
 <sm:message id="4025294">
 <sm:recipient>
 Chris Waterson "waterson@netscape.com"
 </sm:recipient>
 <sm:sender>
 Sarah Waterson "waterson.2@postbox.acs.ohio-state.edu"
 </sm:sender>
 <sm:received-by>x-wing.mcom.com</sm:received-by>
 <sm:subject>We won our ultimate game</sm:subject>
 <sm:body>
 http://www.mozilla.org/smart-mail/get-body.cgi?id=4025294
 </sm:body>
 </sm:message>
 </rdf:Description>
</rdf:RDF>
| John S. Erickson, Ph.D.
| Hewlett-Packard Laboratories
| Norwich, Vermont USA
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