AS3 Cross Movie Global Dispatcher

I have a GlobalDispatcher Singleton class extending EventDispatcher that can be accessed through a static getInstance () method by any class after the constructor has been called.

I have a host movie that calls the GlobalDispatcher constructor and sets up a listener for a custom event. This host movie then dynamically loads in a different external movie (in the same domain as the host). This movie calls the getInstance method to get the instance of the GlobalDispatcher. Then after an animation it has the GlobalDispatcher dispatch the same custom event the host is set to listen to. The host then captures the event dispatched by the dynamically loaded movie.

This works perfectly in authoring environment. But when it is placed on a webpage, run locally or otherwise it doesn’t work.

The dynamically loaded movie does a check to see if there is a valid instance of the constructor available and it says it has not been constructed.

So my question is why would it work in an authoring environment but not in the HTML page? And how can I resolve this? Is there a security setting I am missing?

thank you in advance for your time.