Can't get firsr mc to load

I have a little slide show that works fine. I decided to add a preloader which meant adding a second scene (although its the first one really). So i have a preloader scene, followed by main scene.

Now the first mc wont load (everything works fine when the button is pressed though - its just the opening). I think this is something to do with the fact that I have this in the main scene to load the first slide.

here’s the preloader code

var myInterval:Number;
myInterval = setInterval(preloader, 100);
function preloader() {
 var currentBytes = _root.getBytesLoaded();
 var total = _root.getBytesTotal();
 var pctLoaded = Math.round((currentBytes / total) * 100);
 loaderBar_mc._yscale = pctLoaded;
 if (currentBytes >= total) {
  gotoAndStop("main", 1);

and here’s part of the main code

var currentImage:String = "pic1_mc";
var nextImage:String = "pic2_mc";
var currentIndex:Number=1;
var nextIndex:Number=2;
//number of pictures in the show
var numberPics:Number = 7;
function  animateOn(mcOn:String){

What I have noticed is that pic1_mc is loaded onto the stage, off the LHS which is where it should be. But the play head doesn’t appear to want to go any further.

Has anyone got any ideas please

YOu can see the offending article (its not very exciting!) at - when it loads the stage is gray - background colour - when you press the button the first slide animates off (correctly) but is has never animated on

Thanks in advance