You can't always troubleshoot a Web service or a Web service client by stepping through the code. In many cases, especially those that have to do with interoperability, you need to see the SOAP messages to determine what is going on. The easiest way to do this is to use an HTTP proxy tool such as ProxyTrace (www.pocketsoap.com). With a tool like this you can easily capture the request and response and inspect them for problems. See Chapter 6 for details on using ProxyTrace.