We insisted one of our vendors provide a web service interface, but they are
a PHP shop and barely cobbled together a service, without WSDL. So I hacked
together a WSDL, which seems mostly right, except the generated reference.cs
says the results array consists of one null element. I used a sniffer to
detect the returning SOAP envelope. It looks OK, to me. There should be a
valid string in the results. (Together with the vendor we verified that the
call to their service is working correctly. "ERR02" is a valid test result.)

What am I doing wrong? Below are the generated reference.cs method,
returning SOAP envelope, and pertinent lines of the WSDL I hacked together.

reference.cs:
*************
[System.Web.Services.Protocols.SoapDocumentMethodAttribute("http://soap.vendor.com/create",
RequestNamespace="http://soap.vendor.com",
ResponseNamespace="http://soap.vendor.com",
Use=System.Web.Services.Description.SoapBindingUse.Literal,
ParameterStyle=System.Web.Services.Protocols.SoapParameterStyle.Wrapped)]
       [return:
System.Xml.Serialization.XmlElementAttribute("outputString")]
       public string create(string hid, string src, string fname, string
bname, string domain, string passwd, string email, string tele, string
tzone) {
           object[] results = this.Invoke("create", new object[] {
                       hid,
                       src,
                       fname,
                       bname,
                       domain,
                       passwd,
                       email,
                       tele,
                       tzone});

           return ((string)(results[0]));   //returns with length == 1
(null), I should be recieving "ERR02"
       }

The returning SOAP envelope I detected with HTTP sniffer: (Note extra line
break after "<SOAP-ENV:Body>", shouldn't matter, but I'm stumped).
*******************************************************
<?xml version="1.0" encoding="UTF-8"?>

<SOAP-ENV:Envelope
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/"
xmlns:ns4="http://soap.vendor.com"
SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
<SOAP-ENV:Body>

<ns4:createResponse>
<outputString
xsi:type="xsd:string">ERR02</outputString></ns4:createResponse>
</SOAP-ENV:Body>
</SOAP-ENV:Envelope>

Lines from my WSDL that should be invovled in deciphering the returning SOAP
************************************************************
<wsdl:definitions
...
<wsdl:types>
...
<s:element name="createResponse">
       <s:complexType >
                       <s:sequence>
                                   <s:element minOccurs="0" maxOccurs="1"
name="outputString" type="s:string" />
                       </s:sequence>
        </s:complexType>
     </s:element>
...
</wsdl:types>
...
<wsdl:message name="createSoapOut">
   <wsdl:part name="parameters" element="tns:createResponse" />
 </wsdl:message>
...
<wsdl:portType name="ApiManagerSoap">
   <wsdl:operation name="create">
     <wsdl:input message="tns:createSoapIn" />
     <wsdl:output message="tns:createSoapOut" />
   </wsdl:operation>
...
</wsdl:portType>

<soap:binding transport="http://schemas.xmlsoap.org/soap/http"
style="document" />
   <wsdl:operation name="create">
     <soap:operation soapAction="http://soap.vendor.com/create"
style="document" />
     <wsdl:input>
       <soap:body use="literal" />
     </wsdl:input>
     <wsdl:output>
       <soap:body use="literal" />
     </wsdl:output>
   </wsdl:operation>