Please help: preloader works in simulation but not on the web

I’m trying to preload external swf files as needed and show the progress each time a file is being preloaded. It works exactly as intended when I simulate it on my desktop but not at all when uploaded on the web: first of all nothing happens up until 50% of the main movie is already loaded and then when the the attempt is being made to load additional content, some weird number displays (-214…%) instead of the percentage. Take a look:
I’m also attaching a fla file (104KB):