Hi Adam!
Well, we're both Canadians. Pat is French, but living in California I believe!
If you want to try out the preloader, do this:
Insert a new scene in your Flash 4 Napster project.
Under Window->Inspectors-> hit Scene.
Double click the new scene name, and rename it loader.
Make sure you then drag it towards the top of the list, so that it sits as the first scene.
Now double click the first key frame in the loader scene and add the following actions:
If Frame Is Loaded (Scene 5, "moviend"

Go to and Play (Scene 1, 1)
End Frame Loaded
(This assumes your last scene is scene 5, change it if it's not the case, and that your movie begins on frame 1 of scene 1 - if you have a stop action on frame 1, you should change that also to 2 or the number of your starting frame)
Now insert a new keyframe(F6) on the second frame.
Add the action:
Go to and Play (current scene, 1)
Add a new layer, and just add some text for now like "loading" covering the two actions frames.
The only thing left is to label the last frame of your last scene with "moviend" or the label you have choosen.
That's it. This loader won't be animated ( you can get into that if this one works), but it should do the trick.
Do remember you can't really test this locally. You can simulate the process by choosing Streaming under Control when testing your movie. You should see your text come up and stop, and when you hit enter, the movie should go on playing.
Best way to test it is to upload your movie. Remember to empty your cache to test this first run. Otherwise you won't see the preloader in effect since the files are already present on your machine. Same thing happens to me or any other user after a first download of your movie. After it has downloaded once, I can replay it without seeing the preloader and without interruptions.
Finally, yes using Mp3s instead of wavs should reduce the size of your fla & movie... If you carefully remove the wavs from your project. Beware deleting selected unused items is NOT reversible if you happen to save your project meanwhile!