Server returned an invalid SOAP Fault from C#

FlightAware AeroAPI
1

Hi, im trying to call the SearchBirdseyePositions as show below to test it and see how it works. Its not working for me. getting a soap error:
Message = “End element ‘Fault’ from namespace ‘http://schemas.xmlsoap.org/soap/envelope/’ expected. Found element ‘SOAP-ENV:detail’ from namespace ‘http://schemas.xmlsoap.org/soap/envelope/’. Line 2, position 351.”

  static void Main(string[] args)
    {
        try
        {
            FlightXML2SoapClient client = new FlightXML2SoapClient();
            client.ClientCredentials.UserName.UserName = "XXXXXXXX";
            client.ClientCredentials.UserName.Password = "XXXXXXXX";
            client.SetMaximumResultSize(50);
            ArrayOfTrackExStruct r1 = client.SearchBirdseyePositions("{range lat 36.897669 40.897669} {range lon -79.03655 -75.03655}", true, 50, 0);
            foreach (var e in r1.data)
            {
                Console.WriteLine("Alt= " + e.altitude + " Lat= " + e.latitude + " Lon= " + e.longitude + " TimeStamp= " + e.timestamp);
            }

            Console.ReadLine();
        }
        catch (Exception e)
        {
            string msg = e.Message;
            throw e;
        }
       
    }