(400) Bad Request - when calling a SOAP service with transferMode=Streamed

Question

I am getting (400) Bad Request returned when I call a WCF service via SOAP where the method takes a single parameter of type Stream and the transferMode=Streamed.

I get this exception only when I publish the service using the RouteTable class:

RouteTable.Routes.Add(new ServiceRoute("ping", new ServiceHostFactory(), typeof(PingService)));

If I create a ServiceHost myself then I can call the service with no problems:

host = new ServiceHost(typeof(PingService));
host.Open();

Here is an example of the Service contract:

[ServiceContract]
public interface IPing
{
   [OperationContract]
   Stream Ping(Stream stream);
}

Here is the Web.config:

<configuration>
    <system.web>
        <compilation debug="true" targetFramework="4.0" />
    </system.web>
  <system.serviceModel>

    <serviceHostingEnvironment aspNetCompatibilityEnabled="true"/>

    <services>
      <service name="SoapStreamedWebServiceTest.PingService" behaviorConfiguration="md">
        <endpoint address="" binding="basicHttpBinding" contract="SoapStreamedWebServiceTest.IPing"/>
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="md">
          <serviceMetadata httpGetEnabled="true" />
        </behavior>
      </serviceBehaviors>
    </behaviors>

    <bindings>
      <basicHttpBinding>
        <binding name="stm" transferMode="Streamed"/>
      </basicHttpBinding>
    </bindings>

  </system.serviceModel>
</configuration>

This is only a problem if I create a SOAP service using ServiceHostFactory and basicHttpBinding. If I create a REST service using WebServiceFactory and webHttpBinding then it works fine. However I need to publish both a REST and SOAP endpoint for the same service.

This is also only a problem if the transferMode is Streamed or StreamedRequest, it works for Buffered and StreamedResponse. However I need to allow the consumer to pass me data in a streamed fashion.

If the service is published using the RouteTable then it will return (400) Bad Request when called with transferMode=Streamed without hitting any breakpoint I place within the Ping metod. However if I manually create a Service Host it does hit the breakpoint. I have noticed that the Stream.Lenth property raises an exception when called via SOAP but it does not when called via REST. Could this be anything to do with the problem?

Can anyone shed any light as to why I get (400) Bad Request when calling a SOAP service with transferMode=Streamed when it is published via the RouteTable?