Troubleshooting preloader+sound

I seem to be having trouble with my preloader. At first, after I finish making a certain point in my movie, the preloader doesn’t want to start. Rather, it doesn’t show loading the preloader (which contains a percent# and a scrolling bar). After tinkering around, I realized that the sound file (mp3) was the problem. I deleted it from the library and the preloader had no problem.

I’m using nearly the exact same preloading actions in one of the MX 2004 preloading tutorials:

frame 1 scene 1:
bytes_loaded = Math.round(this.getBytesLoaded());
bytes_total = Math.round(this.getBytesTotal());
getPercent = bytes_loaded/bytes_total;
this.loadBar._width = getPercent141.9;
this.loadText = Math.round(getPercent
100)+"%";
if (bytes_loaded == bytes_total) {
this.gotoAndPlay(3);
fscommand(“showmenu”, “false”); }

frame 2 scene 1:
this.gotoAndPlay(1);

frame 1 scene 2:
MDSound = new Sound(this);
MDSound.attachSound(“mydecembersong”);
MDSound.start(0, 0);

edit:
The song also has linkage in it:
Identifier: mydecembersong
AS 2.0 Class: ‘none’ (whats this?)
Export for Actionscript
Export in first frame

I’m also using the older “snow falling” script but it doesn’t seem to have any effect on the preloader. Any help would be appreciated!!