Flash Interface Unloading Captivate 5.0 works / 5.5 doesn't...why?

Question

TypeError: Error #1009: Cannot access a property or method of a null object reference.
at captivate.veela_as3::rdSwfLoader/rdSwfLoaderEnterFrame()
at captivate.veela_as3::rdEmbeddedSwfPpt/rdSwfLoaderEnterFrame()
Any suggestions welcome - very frustrated by the introduction of this error by Captivate 5.5 - thanks for any help in advance
I've attached some code below - which works perfectly for SWFs created using Captivate 5.0 but an identical recording done with Captivate 5.5 provides the error when unloading.
My Captivate SWF is controlled by an interface SWF (for slide navigation) which is provided inside a menu SWF (which will eventually display several recordings to choose from).  Basically, the menu SWF loads the interface SWF and displays a menu button which unloads the Captivate SWF and the user returns to the menu.
I do wonder if the problem exists because I have CP5.5 installed as a trial version and there could be a conflict between this and the full install of CP5.0.  Incidentally, I did find that if I removed the FMR (Full motion recording) slides the error does disappear on the simulation recordings.  But this doesn't help me with PPT to Captivate recordings where there is no FMR.  Plus I actually want to keep the FMR if possible anyway .  Hope this makes sense.
Menu SWF
stop();
var myLoader:Loader = new Loader();
//Demo 1 Button
demo1but.addEventListener(MouseEvent.CLICK, loadDemo1);
function loadDemo1(event:MouseEvent):void
  demo_title.visible = false;
  body_text.visible = false;
  demo1but.visible = false;
  demo2but.visible = false;
  demo3but.visible = false;
  demo4but.visible = false;
  demo5but.visible = false;
  lines.visible = false;
  inst_txt.visible = false;
        container_mc.addChild(myLoader);
        var url:URLRequest = new URLRequest("http://....../interface.swf");
        myLoader.load(url);
  demo_menu_btn.visible = true; 
dispatchEvent(new Event("actionhideMenuBtn",true));
//Demo Menu Button
demo_menu_btn.addEventListener(MouseEvent.CLICK, returnToDemoMenu);
function returnToDemoMenu(event:MouseEvent):void
       MovieClip(myLoader.content).dispatchEvent(new Event("unloadE"));
    demo_menu_btn.visible = false;
    container_mc.removeChild(myLoader);
    dispatchEvent(new Event("actionrevealMenuBtn",true));
  demo_title.visible = true;
  body_text.visible = true;
  demo1but.visible = true;
  demo2but.visible = true;
  demo3but.visible = true;
  demo4but.visible = true;
  demo5but.visible = true;
  lines.visible = true;
  inst_txt.visible = true;
Interface SWF
import flash.system.fscommand;
import flash.net.URLRequest;
import flash.display.MovieClip;
import flash.media.SoundMixer;
var Xpos: Number = 50
var Ypos: Number = 96
var my_loader:Loader = new Loader();
my_loader.load(new URLRequest("http://....captivate_movie.swf"));
my_loader.x = Xpos;
my_loader.y = Ypos;
this.addEventListener("unloadE",unloadSwf);
function unloadSwf(e:Event):void{
my_loader.unloadAndStop();
addChildAt(my_loader,0);
stop();
//NEXT BUTTON//////////////////////////////////////////////////////////////////////
nextBut.addEventListener(MouseEvent.CLICK, fl_MouseClickHandler);
function fl_MouseClickHandler(event:MouseEvent):void
MovieClip(my_loader.content).rdcmndNextSlide = 1;
//BACK BUTTON//////////////////////////////////////////////////////////////////////
backBut.addEventListener(MouseEvent.CLICK, fl_MouseClickHandler1);
function fl_MouseClickHandler1(event:MouseEvent):void
MovieClip(my_loader.content).rdcmndPrevious = 1;

Answer 1

Think of it this way. Think of the login.oscar.aol.com server as major town and port 5190 as the major highway to get to that town. Of course there are other ways to get to that town via other roads that are open (i.e. other ports that are open).
So if there's a big traffic jam on port 5190, why not choose another road/port (assuming the road/port is open or accepting traffic), such as 443? Consider it the back road that few people know about, in a sense, and maybe that would be why you're seeing better results with this port as opposed to the default port, 5190.
That may or may not be the reason, but that's why a different port works sometimes better than the default port.
-Ryan