SOAP 2.3.1 and Internationalization

Hi Guys,

Apologies if you have seen this question many times before...

I am using Apache SOAP 2.3.1 with JDK 1.4 running on AIX 5.2.

All is setup and working ok.

If I send a simple xml into message into the system, all is fine.

Each message starts:
<?xml version="1.0" encoding="UTF-8" ?>

We are now required to send data that contains non-ascii characters 
(specifically, european accented letters). These are only in the tag 
data, not the tags themselves.

So I changed the message header to:
<?xml version="1.0" encoding="iso-8859-1" ?>

This works fine.

Now the xml data was change to include an accented letter ( passÜxx). 
When I send this data into the server, I get the following response:

<?xml version='1.0' encoding='UTF-8'?>
<SOAP-ENV:Envelope 
xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<SOAP-ENV:Body>
<SOAP-ENV:Fault>
<faultcode>SOAP-ENV:Client</faultcode>
<faultstring>parsing error: org.xml.sax.SAXParseException: XML document 
structures must start and end within the same entity.</faultstring>
<faultactor>/soap/servlet/messagerouter</faultactor>
</SOAP-ENV:Fault>

</SOAP-ENV:Body>
</SOAP-ENV:Envelope>

This is being generated by the SOAP layer before it gets to the web service.

I have written a simple java program that parses theis file using the 
built-in JAXP and that works fine. So I assume that the SOAP layer is 
using an older parser that does not upport internationalization?

I cannot find xerces in any of the tomcat library directories so I am 
puzzeled as to which parser is being used.

Is there a way I can find out what parser is being used and can I slide 
in a newer one ?

Upgrading to Axis is not an option.

Any help gratefully received.
Thanks,
Clive