My company has a Webservice that is currently running in production.  It is
secured using SSL and clients are authenticated using X509 certificates.

I am able to consume the Webservice methods in a Framework 2.0 c# Forms
based application where I instantiate the X509 Certificate by pointing to the
certificate file and passing the password:

//====================
X509Certificate cert = new X509Certificate(this.tbCertFilePath.Text,
this.tbCertificatePassword.Text);

myWebService.ClientCertificates.Add(cert);
string k = myWebService.GetMyDataByYear(2004);
//====================

However, we are trying to instantiate the X509 Certificate using the
LocalMachineStore in a Framework 2.0 c# Web App:

//====================
X509CertificateStore store;
store = X509CertificateStore.LocalMachineStore(X509CertificateStore.MyStore);
byte[] certHash = new byte[]{0x28, 0x83, 0xf0, ...};

bool open = store.OpenRead();
Microsoft.Web.Services2.Security.X509.X509CertificateCollection certs =
   store.FindCertificateByHash(certHash);
Microsoft.Web.Services2.Security.X509.X509Certificate cert = certs[0];

myWebService.ClientCertificates.Add(cert);
string k = myWebService.GetMyDataByYear(2004);
//====================

I am able to verify that the X509 Certificate is in fact being retrieved and
is being placed in the myWebService.ClientCertificates collection.  The
problem occurs when I try to consume the Webservice.  I am getting the
following exceptions:

[SocketException (0x274d): No connection could be made because the target
machine actively refused it]
  System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot,
SocketAddress socketAddress) +1002146
  System.Net.Sockets.Socket.InternalConnect(EndPoint remoteEP) +33
  System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure,
Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState
state, IAsyncResult asyncResult, Int32 timeout, Exception& exception) +431

[WebException: Unable to connect to the remote server]
  System.Net.HttpWebRequest.GetRequestStream() +1504525
  System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String
methodName, Object[] parameters) +103
  DbTest.com.WebServerName.GlobalOrganizerXML.GetAssigneeList(Int32
taxYear) in d:\webapps\DbTest\App_Code\GlobalOrganizerXML.cs:79
  DbTest.WebForm1.Page_Load(Object sender, EventArgs e) in
d:\webapps\DbTest\WebForm1.aspx.cs:65
  System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o,
Object t, EventArgs e) +15
  System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender,
EventArgs e) +34
  System.Web.UI.Control.OnLoad(EventArgs e) +99
  System.Web.UI.Control.LoadRecursive() +47
  System.Web.UI.Page.ProcessRequestMain(Boolean
includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1061

--Thanks in advance