AS3:: How to aviod that unloadAndStop method, stops all my tweens?

programming flash
1

I have such a code:

    var a:Array = new Array(s4_1_arch,btn_back);
    var p:MovieClip = new MovieClip();
    p = MovieClip(parent);
    var url:URLRequest;
    var myLoader:Loader = new Loader();
    var loaded:Boolean;
    
    function samClick(e:MouseEvent):void
    {
        trace(e.target.name);
        switch (e.target)
        {
            case s4_1_arch :
                loaded = true;
    
                if (loaded)
                {
                    url = new URLRequest("gallery.swf");
                    stage.addChild(myLoader);
                    myLoader.load(url);
                    var loaderTween:Tween = new Tween(myLoader,"alpha",Strong.easeIn,0,1,1,true);
                    s4_1_arch.removeEventListener(MouseEvent.CLICK, samClick);
                }
            break;
    
            case btn_back :
                if (loaded)
                {
                    myLoader.unloadAndStop();
                    stage.removeChild(myLoader);
                    loaded = false;
                    trace(myLoader.stage);
    
                    s4_1_arch.addEventListener(MouseEvent.CLICK, samClick);
                    var btn1back:Tween = new Tween(p.btn1,"y",Strong.easeOut,p.btn1.y,-150,1,true);
                    var btn2back:Tween = new Tween(p.btn2,"y",Strong.easeOut,p.btn2.y,-110,1,true);
                    var btn3back:Tween = new Tween(p.btn3,"y",Strong.easeOut,p.btn3.y,-70,1,true);
                    var btn4back:Tween = new Tween(p.btn4,"y",Strong.easeOut,p.btn4.y,-30,1,true);
                    var btn5back:Tween = new Tween(p.btn5,"y",Strong.easeOut,p.btn5.y,10,1,true);
                    var btn6back:Tween = new Tween(p.btn6,"y",Strong.easeOut,p.btn6.y,50,1,true);
                    var btn7back:Tween = new Tween(p.btn7,"y",Strong.easeOut,p.btn7.y,90,1,true);
                    var btn8back:Tween = new Tween(p.btn8,"y",Strong.easeOut,p.btn8.y,130,1,true);
                    var submenu4:Tween = new Tween(p.btn4_sub,"x",Strong.easeOut,p.btn4_sub.x,270,1,true);
                    var submenu4up:Tween = new Tween(p.btn4_sub,"y",Strong.easeOut,p.btn4_sub.y,0,1,true);
                    submenu4up.addEventListener(TweenEvent.MOTION_FINISH, doSomeStuff);
                }
   
    for (var i:Number = 0; i < 2; i++)
    {
        a*.addEventListener(MouseEvent.CLICK, samClick);
    }

My problem is that the method unloadAndStop - stops all my tweens.

I tried to use the method unload, and all works, but when i click again on the button s4_1_arch everything works fine, but i get this error:

    TypeError: Error #1009:  Cannot access a property or method of a null object reference.
    at Function/<anonymous>()

I also tried to use this code:

    if (loaded)
    {
        myLoader.unloadAndStop();
        stage.removeChild(myLoader);
        loaded = false;
        trace(myLoader.stage);
    }
    else
    {
        s4_1_arch.addEventListener(MouseEvent.CLICK, samClick);
        var btn1back:Tween = new Tween(p.btn1,"y",Strong.easeOut,p.btn1.y,-150,1,true);
        //all my Tweens
    }

In this case the tweens works when i click the button btn_back the second time.

I need to unload and play tweens at once without output errors.

Can anyone help?