IIS6 configuration for WCF/Silverlight

I am trying the simple senario of running a WCF service to return Active directory information on a user. (http://rouslan.com/2009/03/20-steps-to-get-together-windows-authentication-silverlight-and-wcf-service/) using Silverlight 4 & .net 4

However, I am being driven insane by trying to set this up in IIS. Currently I have my solution working in VS, but when I try to run the service in ISS a debug window tries to open... (and I can't get rid of it, is is com开发者_JAVA百科plaining about the WCF call).

<basicHttpBinding>
    <binding name="winAuthBasicHttpBinding">
        <security mode="TransportCredentialOnly">
            <transport clientCredentialType="Ntlm"/>
        </security>
    </binding>
</basicHttpBinding>

My next step is to install Server2008 on a test machine and try IIS7... as all the various walkthrough's I have found just dont seem to work in IIS6.

Image: http://www.freeimagehosting.net/image.php?54d5202ffb.jpg

It all worked fine with my 2008 server, it also worked fine when I set up another developer box.

So there was something weird happening in my dev environment.