WebService Client Certificate Problem

[Koan B]

(Cross-posted to dotnet.framewor k.aspnet.webser vices and
dotnet.framewor k.webservices, follow-ups set to
dotnet.framewor k.aspnet.webser vices)

Hi,

I'm attempting to connect to a 3rd party web service (for which they
have supplied client certificates), but with no success.

As far as I can tell, the code below should work, however, I always
get back an HTTP 403 (Forbidden) error returned. (I've also tried
loading the certificate from the certificate store with exactly the
same result.

I'm using a WSDL file as the basis for the interface to a web service
and using the following code (based on MSDN documentation):

/////////////////////////////////////////////////////////////////////
service = new RequestService( );

// certificate is the path to a DER encoded x509 certificate
X509Certificate x509 =
X509Certificate .CreateFromCert File(certificat e);
service.ClientC ertificates.Add (x509);

// Create a request object
RequestType request = new RequestType();
// Build request

// MakeRequest method of the service
ReplyType reply = service.MakeReq uest(request);
/////////////////////////////////////////////////////////////////////

Cheers,

Koan