How to get rid of the blink between photo transistion?

programming flash
1

zie http://www.bldd.nl/flashproblems/photoSlideshow3.swf

i see a blink right after my animated mask is finished


stop();
var myMCL:MovieClipLoader = new MovieClipLoader();
var myMCL2:MovieClipLoader = new MovieClipLoader();
var maxNrOfPhotos:Number = 4;
var photoHolderTop:MovieClip;
var photoHolderBottom:MovieClip;
function startSlideShow() {
	trace("halllo");
	var nummer:Number = 1;
	var nummer2:Number = nummer +1;
	var myListener:Object = new Object();
	myMCL.addListener(myListener);
	//myMCL2.addListener(myListener);
	myMCL.loadClip("photos/photo"+nummer2+".jpg", photoHolderTop);
	myMCL2.loadClip("photos/photo"+nummer+".jpg", photoHolderBottom);	
	myListener.onLoadInit = function(photoHolderTop) {
		trace("Nummer: "+nummer+" Nummer2: "+nummer2);
		if (nummer< maxNrOfPhotos) {
			nummer++;
		} else {
			nummer = 1;
		}
		if (nummer2<maxNrOfPhotos) {
			nummer2 = nummer + 1;
		} else {
			nummer2 = 1;
		}	
		photoHolderBottom._visible = true;
		photoHolderTop._visible = true;
		photoHolderTop.setMask(masker);
		masker.gotoAndPlay("_start");
		setTimeout(loadNext, 5500, nummer, nummer2);
	};

}
startSlideShow();
function loadNext(nummer:Number, nummer2:Number) {
	myMCL.loadClip("photos/photo"+nummer2+".jpg", photoHolderTop);
	myMCL2.loadClip("photos/photo"+nummer+".jpg", photoHolderBottom);
	photoHolderBottom._visible = true;
	photoHolderTop._visible = true;
}