org.xml.sax.SAXParseException

Hi all,
On sending out a SOAP request using the perl SOAP library, I was returned
the following error -

<soapenv:Body>
  <soapenv:Fault>
   <faultcode>soapenv:Server.userException</faultcode>
   <faultstring>org.xml.sax.SAXParseException: Element or attribute do not
match QName production: QName::=(NCName&apos;:&apos;)?NCName. </faultstring>
   <detail/>
  </soapenv:Fault>
 </soapenv:Body>

I have no idea what the fault string means. Any clue or ideas on this or
where I can know what it means?

Thanks.
-Anshuman