Schema Compliance - FAILED -> line -1: null

I have a schema compliance assertion which fails with "line -1: null" on this fault message:

HTTP/1.1 500 Internal Server Error
Date: Fri, 17 Jun 2011 20:24:55 GMT
Transfer-Encoding: chunked
Content-Type: application/soap+xml;charset="utf-8"
X-ORACLE-DMS-ECID: 0000J2VHlopFw0YFLrqIOA1DyuDs0000qn
X-Powered-By: Servlet/2.5 JSP/2.1

<?xml version='1.0' encoding='UTF-8'?>
<S:Envelope xmlns:S="http://www.w3.org/2003/05/soap-envelope">
  <S:Body>
    <S:Fault xmlns:ns4="http://schemas.xmlsoap.org/soap/envelope/">
      <S:Code>
        <S:Value>S:Receiver</S:Value>
      </S:Code>
      <S:Reason>
        <S:Text xml:lang="en">com.example.network.npp.SMSCAdapter.AdapterFaultMessage</S:Text>
      </S:Reason>
      <S:Detail>
        <ns7:AdapterFault xmlns:ns8="http://www.example.com/network/NPP/provisioning/tnservice"
                          xmlns:ns6="http://www.example.com/network/NPP/base/transaction" xmlns:ns5="http://www.example.com/network/NPP/base/service"
                          xmlns:ns4="http://www.example.com/network/NPP/base/net" xmlns:ns3="http://www.example.com/network/NPP/base/identity"
                          xmlns:ns2="http://www.example.com/network/NPP/base/entity" xmlns="http://www.example.com/network/NPP/base/device"
                          xmlns:ns7="http://www.example.com/network/NPP/adapter/smscservice">
          <ns7:nppTxId>
            <ns6:nppTransactionId>12345</ns6:nppTransactionId>
            <ns6:nppTimestamp>456</ns6:nppTimestamp>
            <ns6:nppIsRetryFlag>false</ns6:nppIsRetryFlag>
          </ns7:nppTxId>
          <ns7:clientTxId>
            <ns6:clientUserId>V21</ns6:clientUserId>
            <ns6:transactionId>600001</ns6:transactionId>
            <ns6:isRetry>false</ns6:isRetry>
          </ns7:clientTxId>
          <ns7:error>
            <ns6:errorClass>2</ns6:errorClass>
            <ns6:errorCode>11350</ns6:errorCode>
            <ns6:timestamp>2011-06-17 16:24:56 -0500</ns6:timestamp>
            <ns6:systemType>SMSCAdapter</ns6:systemType>
            <ns6:errorMessage>SMSCAdapter Exception: null</ns6:errorMessage>
          </ns7:error>
        </ns7:AdapterFault>
        <ns2:exception xmlns:ns2="http://jax-ws.dev.java.net/" class="com.example.network.npp.SMSCAdapter.AdapterFaultMessage"
                       note="To disable this feature, set com.sun.xml.ws.fault.SOAPFaultBuilder.disableCaptureStackTrace system property to false">
          <ns2:stackTrace>
            <ns2:frame class="com.example.network.npp.SMSCAdapter.NppSmscAdapterImpl" file="NppSmscAdapterImpl.java" line="90"
                       method="smscCreateService"/>
          </ns2:stackTrace>
        </ns2:exception>
      </S:Detail>
    </S:Fault>
  </S:Body>
</S:Envelope>

The WSDL appears to be correct and passes XML validation, and the fault message validates against the schema using other tools.

I have attached the WSDL.

Is some subtle error in the WSDL, or a soapUI problem?

Thanks.