Why does URLStream complete event get dispatched when the file is not finished loading?

Question

I'm writing an AIR kiosk app that every night connects to a WordPress server, gets a JSON file with paths to all the content, and then downloads that content and saves it to the kiosk hard drive. 
There's several hundred files (jpg, png, f4v, xml) and most of them download/save with no problems.  However, there are two f4v files that never get downloaded completely.  The complete event does get dispatched, but if I compare the bytesTotal (from the progress event) vs bytesAvailable (from the complete event) they don't match up; bytesTotal is larger.  The bytesTotal (from the progress event) matches the bytes on the server. 
The bytesLoaded in the progress event never increases to the point that it matches the bytesTotal so I can't rely on the progress event either.  This seems to happen on the same two videos every time. The videos are not very large, one is 13MB and the other is 46MB.  I have larger videos that download without any problems.  
[edit] After rebooting the compter, the two videos that were failing now download correctly, and now it's a 300kb png file that is not downloading completely.  I'm only getting 312889 of 314349 bytes.
If I paste the url into Firefox it downloads correctly, so it appears to be a problem with Flash/AIR.
[edit] I just wrote a quick C# app to download the file and it works as expected, so it's definitely a problem with Flash/AIR. 
Here's the code I'm using:
package  {
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.ProgressEvent;
    import flash.net.URLRequest;
    import flash.net.URLStream;
    [SWF(backgroundColor="#000000", frameRate="24", width="640", height="480")]
    public class Test extends Sprite {
        private var fileSize:Number;
        private var stream : URLStream;
        private var url:String = "http://192.168.150.219/wordpress2/wp-content/uploads/2012/12/John-Butler-clip1.f4v";
        public function Test() {
            if (stage)
                init();
            else
                this.addEventListener(Event.ADDED_TO_STAGE, init);
        private function init(e:Event=null):void {
            this.removeEventListener(Event.ADDED_TO_STAGE, init);
            stream = new URLStream();
            stream.addEventListener(ProgressEvent.PROGRESS, onLoadProgress);
            stream.addEventListener(Event.COMPLETE, onLoadComplete);
            stream.load(new URLRequest(url));
        private function onLoadProgress(event:ProgressEvent):void {
            fileSize = event.bytesTotal;
            var percent:Number = event.bytesLoaded / event.bytesTotal * 100;
            trace(percent + "%");
        private function onLoadComplete(event:Event):void {
            trace("loaded", stream.bytesAvailable, "of", fileSize);
            // outputs "loaded 13182905 of 13184365"
            // so why is it "complete" when it isn't finished downloading?

Answer 1

Thanks for your quick reply !
I am relatively new to programming so please bear with me on this as I still haven't managed to grasp some of those things that "make perfect sense". If I am setting mouseEnabled to false doesn't that mean that the object no longer gets MouseEvents ?
If I have understood you correctly then once the mouseEnabled is set to false the btn object is removed from the objects recognizable by the mouse - hence dispatching a mouseout event (and I am guessing here) from the mouse?
I still don't get it though, if the listeners are set to the object and the object is no longer accessible to the mouse why is the event still being dispatched ?
I get it that the making of the object unavailable to the mouse causes the "removing" (deactivating) of the object from under the mouse,
  step 1. deactivate object, and  step 2. (as a result of step 1) register the removal of the object.
but why is the mouse still listening after step 1?
Even if the action is that of "out" (as in the object is no longer under the mouse) it still is an action isn't it ? so haven't we turned off the listening for actions ?
I promise I am not trying to drive you crazy here, this is just one of those things that I really want to get to the root of !
Thanks,