Silverlight IIS6 with windows authentication deployment

Question

After a series of extremely frustrating failures I managed to set up Silverlight using windows authentication following these steps in iis7.5 http://rouslan.com/2009/03/20-steps-to-get-together-windows-authentication-silverlight-and-wcf-service/

(I had to build my own windows server box, which was a learning experience in itself).

However, our environment uses IIS6, and I cant get anything to work in IIS6. From what I have read all I should have to do is:

1. Changed <transport clientCredentialType="Windows" /> to <transport clientCredentialType="Ntlm" />
2. Removed the "mexHttpBinding" bindings from my services' sections in Web.config.
3. Turn on Anonymous access in IIS

But, I have done all of this and when I try and run my Silverlight web site I get a username and password screen that (that does not work!)

Unfortunately this means we may end up dumping Silverlight entirely, and I certainly do not want that to happen ;(

NOTE: The service works with a consol app.

Copy of my Web.Config File

<?xml version="1.0"?>
<configuration>
    <connectionStrings>
  <add name="TTASConnectionString" connectionString="Data Source=stdev07;Initial Catalog=IRF;Integrated Security=True"
   providerName="System.Data.SqlClient" />
  <add name="PlaygroupConnectionString" connectionString="Data Source=WIN-B1JAITZ6H0N;Initial Catalog=Playgroup;Integrated Security=True"
   providerName="System.Data.SqlClient" />
 </connectionStrings>
 <system.diagnostics>
  <sources>
   <source name="System.ServiceModel.MessageLogging" switchValue="Warning, ActivityTracing">
    <listeners>
     <add type="System.Diagnostics.DefaultTraceListener" name="Default">
      <filter type="" />
     </add>
     <add name="ServiceModelMessageLoggingListener">
      <filter type="" />
     </add>
    </listeners>
   </source>
   <source name="System.ServiceModel" switchValue="Warning, ActivityTracing"
    propagateActivity="true">
    <listeners>
     <add type="System.Diagnostics.DefaultTraceListener" name="Default">
      <filter type="" />
     </add>
     <add name="ServiceModelTraceListener">
      <filter type="" />
     </add>
    </listeners>
   </source>
  </sources>
  <sharedListeners>
   <add initializeData="C:\Users\Administrator\Documents\Visual Studio 2010\Moe.Tactical.Irf.Silverlight\Moe.Tactical.GenericData.Wcf\Web_messages.svclog"
    type="System.Diagnostics.XmlWriterTraceListener, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
    name="ServiceModelMessageLoggingListener" traceOutputOptions="Timestamp">
    <filter type="" />
   </add>
   <add initializeData="C:\Users\Administrator\Documents\Visual Studio 2010\Moe.Tactical.Irf.Silverlight\Moe.Tactical.GenericData.Wcf\Web_tracelog.svclog"
    type="System.Diagnostics.XmlWriterTraceListener, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
    name="ServiceModelTraceListener" traceOutputOptions="Timestamp">
    <filter type="" />
   </add>
  </sharedListeners>
 </system.diagnostics>
 <appSettings/>
    <system.web>
        <compilation debug="true" targetFramework="4.0">
        </compilation>
        <!--
        The <authentication> section enables configuration 
        of the security authentication mode used by 
        ASP.NET to identify an incoming user. 
    -->
        <authentication mode="Windows"/>
        <!--
        The <customErrors> section enables configuration 
        of what to do if/when an unhandled error occurs 
        during the execution of a request. Specifically, 
        it enables developers to configure html error pages 
        to be displayed in place of a error stack trace.

        <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
         <error statusCode="403" redirect="NoAccess.htm" />
         <error statusCode="404" redirect="FileNotFound.htm" />
        </customErrors>
    -->
        <pages controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID"/></system.web>
    <!-- 
      The system.webServer section is required for running ASP.NET AJAX under Internet
      Information Services 7.0.  It is not necessary for previous version of IIS.
  -->
    <system.serviceModel>
        <diagnostics>
   <messageLogging logMalformedMessages="true" logMessagesAtTransportLevel="true" />
  </diagnostics>
  <extensions>
   <behaviorExtensions>
    <add name="silverlightFaults" type="Moe.Tactical.GenericData.Wcf.SilverlightFaultBehavior, Moe.Tactical.GenericData.Wcf, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
   </behaviorExtensions>
  </extensions>
  <serviceHostingEnvironment aspNetCompatibilityEnabled="true"/>
        <bindings>
            <basicHttpBinding>
                <binding name="winAuthBasicHttpBinding">
                    <security mode="TransportCredentialOnly">
                        <transport clientCredentialType="Ntlm"/>
                    </security>
                </binding>
            </basicHttpBinding>
        </bindings>
        <services>
            <service behaviorConfiguration="Moe.Tactical.GenericData.Wcf.GenericDataServiceBehavior" name="Moe.Tactical.GenericData.Wcf.GenericDataService">                
                <endpoint address=""
                  binding="basicHttpBinding"
                  bindingConfiguration="winAuthBasicHttpBinding"
                  behaviorConfiguration="SilverlightFaultBehavior"
                  contract="Moe.Tactical.GenericData.Wcf.IGenericDataService">
                    <identity>
                        <dns value="localhost"/>
                    </identity>
                </endpoint>
                <!--<endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>-->
            </service>
        </services>
        <behaviors>
   <endpointBehaviors>
    <behavior name="SilverlightFaultBehavior">
     <silverlightFaults />
    </behavior>
   </endpointBehaviors>
   <serviceBehaviors>
    <behavior name="Moe.Tactical.GenericData.Wcf.GenericDataServiceBehavior">
     <serviceMetadata httpGetEnabled="true" />
     <serviceDebug includeExceptionDetailInFaults="true" />
    </behavior>
   </serviceBehaviors>
  </behaviors>

  </system.serviceModel>

</configuration>