Please help with external swf preload code

The basis of this question is why my code won’t work to preload an external swf into my main swf. I’ve received help from this forum and others on other ways to do this (Thanks Claudio!), but I can’t stop thinking about why my original plan didn’t work. Plus, I like this preloader, and it’s simplicity, and would like to use it as is, with any necessary changes.

I have a main swf this calls the external swf using:

_root.createEmptyMovieClip("container", 1);
loadMovie("externalpreloader.swf", "container");
setProperty ("container", _alpha, "45");
container._x = 64 ;
container._y = 135 ;

I’ve attached an example fla like the external swf I’m trying to load, and you can see the preloader I’m using in that file. All that happens when this swf is brought in is a quick flash of the outline for the preloader and then the swf starts playing. It’s not just because of the small size either, because no matter how big I’ve made the swf, that’s all it ever does. I think it must have something to do with referring to _root, but I don’t know how to change it! To test it add a large pic or sound file on the frame that I just drew a rectangle. Thanks for any help!:

NOTE: This preloader works fine stand alone…just not when loaded into the main swf