parsing SOAP server response

I'm attempting to parse a SOAP response with Xerces, and things are  
looking fine but for the encodingStyle attribute of the 'Envelope'  
element.

The beginning of a SOAP envelope is something like this:

---
<?xml version="1.0" encoding="ISO-8859-1"?><SOAP-ENV:Envelope SOAP- 
ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"  
xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema 
" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:SOAP- 
ENC="http://schemas.xmlsoap.org/soap/encoding/"><SOAP-ENV:Body>...
---

I grabbed the Schema file for the envelope here from http://schemas.xmlsoap.org/soap/encoding/ 
  (BTW, how can I tell Xerces to get '/' if there is no actual server  
file name associated with a URL?), named it 'soap-envelope.xsd', and  
setExternalSchemaLocation() to be 'http://schemas.xmlsoap.org/soap/envelope/ 
  soap-envelope.xsd'.

Upon parsing the response, I get a validation error:

Attribute '{http://schemas.xmlsoap.org/soap/envelope/}encodingStyle'  
is not declared for element 'Envelope'.

If I add the 'http://schemas.xmlsoap.org/soap/encoding/ soap- 
encoding.xsd' string to the setExternalSchemaLocation call, it  
complains upon parsing the encoding Schema file.

Removing the attribute from the XML allows parsing subsequently - I'm  
sure there's something basic that I'm missing here - any pointers?

Thank you!
-lev