We are trying to log Web Service Requests using a SOAP Extension.  We have
about 10 different web services, and we do not want to modify any of them.  
The only thing we would like to modify is the machine.config on the web
services server i.e.

<webServices>
    <soapExtensionTypes>
        <add type="WebServiceTrace.WebServiceTrace,WebServiceTrace" priority="1" />
    </soapExtensionTypes>
</webServices>

However, the SOAP Extension is never called.  What are we doing wrong?

For testing we are only using one web service and modifying it's web.config.
That shouldn't be any different than modifying the machine.config, once it
goes to production, correct?

Below is the ProcessMessageSection of our WebServiceTraceClass,

Public Overrides Sub ProcessMessage(ByVal message As SoapMessage)
       Select Case message.Stage
           Case SoapMessageStage.BeforeSerialize
               ' do nothing
           Case SoapMessageStage.AfterSerialize
               'WriteOutput(message)
           Case SoapMessageStage.BeforeDeserialize
               WriteInput(message)
           Case SoapMessageStage.AfterDeserialize
               ' do nothing
           Case Else
               Throw New Exception("invalid stage")
       End Select
   End Sub

We are inheriting the SoapExtension class.

Thanks,