// Loading a SWF from a remote server requires you to set the correct securityDomain
// Use the Security.sandboxType to check this
// Testing a SWF locally doesn't require securityDomain
// In a browser it does (Security.REMOTE)
 
import flash.system.*;
import flash.net.*;
 
if(Security.sandboxType == Security.REMOTE)
{
  var context:LoaderContext = new LoaderContext();
  context.securityDomain = SecurityDomain.currentDomain;
}
 
var ldr:Loader = new Loader();
ldr.load(new URLRequest("http://www.remoteDomain.com/remoteSWF.swf"), context);