Flash Remoting and Actionscript

The following code, according to the debug window, connects successfully and gets an array back from amfphp. However, the responder onResult does not load the array into the combobox. This code is a simplified form of coed in O'reilley's Flash Remoting: The Definitive Guide with a php "northwind" database. The amfphp service browser also works fine. Basically, the only thing in my flash movie is a combobox w/ the instance name of countries_cb... I added the last line at the end to make sure I could write a value/label pair to the combobox...and it works...so for some reason the responder is not getting invoked...The code is below.

Obviously I'm new and this should be simple...I just am not sure how to make sure actionscript is invoking the onResult responder...and I've searched until my heart's content...thanks in advance...

import mx.remoting.Service;

   import mx.rpc.RelayResponder;
   import mx.remoting.PendingCall;
   import mx.remoting.debug.NetDebug;
   import mx.services.Log;

//-------------------------------------------------------------------
// Define the URLs
//-------------------------------------------------------------------
gatewayURL = "http://dfwhomesales.com/flashservices/gateway.php";
serviceURL = "CustomersAdmin";

countryResponder = new Object( );
countryResponder.onResult = function (countries_rs) {
  var max = countries_rs.getLength( );

  countries_cb.setEnabled(true);
  countries_cb.addItem("All", 0);

  for (var i=0; i<max; ++i) {
    countries_cb.addItem(countries_rs.getItemAt(i).Country, i+1);
  }
  countries_cb.setSelectedIndex(0);

 
};

//-------------------------------------------------------------------
// Create the gateway and service objects
//-------------------------------------------------------------------

this.service = new Service(this.gatewayURL, new Log(), "CustomersAdmin", null, null);
service.getCountries(countryResponder);
countries_cb.addItem("All", 0);