Scroll Problem but only Online

Hey ppl, I’m editing this template but there is a problem, when the page is online the scroll sometime doesnt work

http://www.s2.com.pt/uniovo/main.html

I don’t understand why, in the swf everything is perfect, but when the page is online if we test the scroll sometimes it simply doesn’t work !

The scroll code is:


	max = pagina_txt.maxscroll;
	vis = pagina_txt.maxviewable()
	visPercent = (vis/max)*100
	topOfScroll=scrollbg_mc._y;
	dragHeight=scrollbg_mc._height-dragger_mc._height;
	amountPerScroll=dragHeight/max;
	
	dragger_mc.onPress=function(){
		startDrag(this,false,scrollbg_mc._x,scrollbg_mc._y,scrollbg_mc._x,(scrollbg_mc._y+scrollbg_mc._height)-this._height);
		this.onEnterFrame=function(){
			amountFromTop=this._y-topOfScroll
			newScroll=Math.floor(amountFromTop/amountPerScroll)+1
			pagina_txt.scroll=newScroll
		}
	}
	
	dragger_mc.onRelease = dragger_mc.onReleaseOutside=function(){
		this.onEnterFrame=null;
		dragger_mc.grip.gotoAndPlay(11);
		stopDrag();
	}
	
	dragger_mc.onRollOver = function(){
		dragger_mc.grip.gotoAndPlay(2);
		}
	
	dragger_mc.onRollOut = dragger_mc.onReleaseOutside = function(){
		this.onEnterFrame=null;
		dragger_mc.grip.gotoAndPlay(11);
		stopDrag();
		}
	
}




TextField.prototype.maxviewable = function() {
	if (this.maxscroll>1) return this.bottomScroll;
	var b = (this.text) ? this.bottomScroll-1 : this.bottomScroll;
	if (!this.length) this.text = "»";
	var out = Math.floor(this._height/(this.textHeight/b));
	if (this.text == "»") this.text = "";
	return out;
};


but offline everything is ok !

Can anyone give me any clue ?

Tks