Sign a XML file by SmartCard on the .NET

// Example C#
// Open the My certificate store.
   X509Store storeMy = new X509Store(StoreName.My,
      StoreLocation.CurrentUser);
   storeMy.Open(OpenFlags.ReadOnly);
   X509Certificate2Collection  certs=X509Certificate2UI.SelectFromCollection   
      (storeMy.Certificates, "Selection", "Select a certificate", 
      X509SelectionFlag.SingleSelection);
   X509Certificate2 cert=certs[0];
   storeMy.Close();
 
   // Returns TRUE
   cert.HasPrivateKey;
 
   /* Here i receive a System.Security.Cryptography.CryptographicException: cryptographic service provider (CSP) does not support this key algorithm (It occurs only when i am accessing the private key of the certificate stored on the chip card...if the certificate with private key is stored on the machine certificate store it works well..)*/
   cert.PrivateKey;
 
//Example Delphi® 2007 for Microsoft® .NET
var
  vCertificados : X509Certificate2Collection;
  vStore : X509Store;
begin
  vStore        := nil;
  vCertificados := nil;
  try
    Result := False;
    vStore := X509Store.Create;
    vStore.Open(OpenFlags.ReadOnly);
    vCertificados := vStore.Certificates;
    vCertificados := X509Certificate2UI.SelectFromCollection(vCertificados, "Selection", "Select a certificate", X509SelectionFlag.SingleSelection);
// Returns TRUE
   vCertificados[0].HasPrivateKey;
 
   /* Here i receive a System.Security.Cryptography.CryptographicException: cryptographic service provider (CSP) does not support this key algorithm (It occurs only when i am accessing the private key of the certificate stored on the chip card...if the certificate with private key is stored on the machine certificate store it works well..)*/
   vCertificados[0].PrivateKey;
    vStore.Close;
  finally
    vStore.Free;
    vCertificados.Free;
  end;
end;