[wvxvw]

Угу, Application не является документ классом флексовой SWF, так что если loadedSWF as IModule == null -> Читаем тут:

/**
	 *  @private
	 *  If a class wants to be notified when the Application instance
	 *  has been initialized, then it registers a callback here.
	 *  By using a callback mechanism, we avoid adding unwanted
	 *  linker dependencies on classes like HistoryManager and DragManager.
	 */
	mx_internal static function registerInitCallback(initFunction:Function):void
	{
		if (!allSystemManagers || !lastSystemManager)
		{
			return;
		}
 
		var sm:SystemManager = lastSystemManager;
 
		// If this function is called late (after we're done invoking the
		// callback functions for the last time), then just invoke
		// the callback function immediately.
		if (sm.doneExecutingInitCallbacks)
			initFunction(sm);
		else
			sm.initCallbackFunctions.push(initFunction);
	}

И делаем выводы

а так же:

//----------------------------------
    //  application
    //----------------------------------
 
	/**
	 *  The application parented by this SystemManager.
	 *  SystemManagers create an instance of an Application
	 *  even if they are loaded into another Application.
	 *  Thus, this may not match mx.core.Application.application
	 *  if the SWF has been loaded into another application.
	 *  <p>Note that this property is not typed as mx.core.Application
	 *  because of load-time performance considerations
	 *  but can be coerced into an mx.core.Application.</p>
	 */
	public function get application():IUIComponent
	{
		return IUIComponent(_document);
	}