ActionScript 2.0 :: Looping MP3s Seamlessly Unless Mute Button Clicked?

I'm using some modified code from a chapter exercise (from a text book) to play four separate MP3s external to the FLA. Here's an example of what happens when a button is clicked:

Code:
BtnOne.onRelease = function():Void {
stopAllSounds();
song1=new Sound();
song1.loadSound("Music/Puffy.mp3", true);
gotoAndPlay("music1");

On the label 'music1', I have this AS:
Code:
stop();
song1.onSoundComplete = function() {
song1.start();
}

The problem is, there's something of a noticeable stutter when the MP3 reaches the end, just before it starts up again. The first MP3 (contrary to the others), is a seamless ambient sound which ought to sound perfect in the FLA, but doesn't, again, because of the slight stutter in starting it up again. Is there a better way to do this? I thought, perhaps, this would be fixed if I removed the "stop();" line and instead had it play the next frame, which would invariably send it back to the previous one, but this changed nothing. Is there a better method to use? Even with the other three MP3s, which aren't seamless, I want to loop, unless and until the user clicks the 'Mute' button.