buttons stop working randomly

Hi Im doing a youtube masthead banner with multiple video players. the problem that I have is that on certain times the buttons from the right side stop working, and sometimes also the ones from the left, I dont know what can be creating that.

This is the code that I use with the video, and the buttons. And here is the swf so u can try and see the error http://alejuu.com/demo/vice/banner/YT_Masthead_970x250_parent.swf

import flash.events.MouseEvent;

import com.google.ads.studio.events.StudioEvent;

stop();

Security.allowDomain("www.youtube.com");

var videoPlayer:Object;

var loader:Loader = new Loader();

     loader.contentLoaderInfo.addEventListener(Event.INIT, onLoaderInit);

     loader.load(new URLRequest("http://www.youtube.com/apiplayer?version=3"));

function onLoaderInit(event:Event):void {

     addChild(loader);

     loader.content.addEventListener("onReady", onPlayerReady);

}

function onPlayerReady(event:Event):void {

     trace("Ready");

     videoPlayer = loader.content;

     videoPlayer.setSize(230, 172); //PUT THE DIMENSIONS OF YOUR VIDEO IN THIS LINE

     videoPlayer.loadVideoByUrl("http://www.youtube.com/v/Eo9V0FrKGu8", 0);//PUT YOUR VIDEO URL IN THIS LINE

     videoPlayer.x = stage.stageWidth/2.0 - videoPlayer.width/2.0;

     videoPlayer.y = stage.stageHeight/1.60 - videoPlayer.height/1.60;

}

function  playRockabilly(event:MouseEvent)

{

    gotoAndStop(3);

}

rockabilly.buttonMode = true;

rockabilly.useHandCursor = true;

rockabilly.addEventListener(MouseEvent.MOUSE_OVER, playRockabilly);

function  playBiker(event:MouseEvent)

{

    gotoAndStop(4);

}

biker.buttonMode = true;

biker.useHandCursor = true;

biker.addEventListener(MouseEvent.MOUSE_OVER, playBiker);

function  playHiphop(event:MouseEvent)

{

    gotoAndStop(5);

}

hiphop.buttonMode = true;

hiphop.useHandCursor = true;

hiphop.addEventListener(MouseEvent.MOUSE_OVER, playHiphop);

function  playCholo(event:MouseEvent)

{

    gotoAndStop(6);

}

cholo.buttonMode = true;

cholo.useHandCursor = true;

cholo.addEventListener(MouseEvent.MOUSE_OVER, playCholo);

function  playSurf(event:MouseEvent)

{

    gotoAndStop(7);

}

surf.buttonMode = true;

surf.useHandCursor = true;

surf.addEventListener(MouseEvent.MOUSE_OVER, playSurf);

function  playRock(event:MouseEvent)

{

    gotoAndStop(8);

}

rock.buttonMode = true;

rock.useHandCursor = true;

rock.addEventListener(MouseEvent.MOUSE_OVER, playRock);

function  playOtaku(event:MouseEvent)

{

    gotoAndStop(9);

}

otaku.buttonMode = true;

otaku.useHandCursor = true;

otaku.addEventListener(MouseEvent.MOUSE_OVER, playOtaku);

function  playSkate(event:MouseEvent)

{

    gotoAndStop(10);

}

skate.buttonMode = true;

skate.useHandCursor = true;

skate.addEventListener(MouseEvent.MOUSE_OVER, playSkate);

function  playHinrgy(event:MouseEvent)

{

    gotoAndStop(11);

}

hinrgy.buttonMode = true;

hinrgy.useHandCursor = true;

hinrgy.addEventListener(MouseEvent.MOUSE_OVER, playHinrgy);