AS3 nested mc button doesn't respond

I'm using AS3 timeline actions. I have a movie clip nested in another movie clip, which has five buttons. The code is on the parent movie clip's timeline. The buttons activate movie clips with tweens. I wonder why the buttons need to be clicked several times before I see the tween movie clips appear. Some times the movie doesn't even show up.

Is it a script problem or something else?

stop();
import fl.transitions.Tween;
import fl.transitions.easing.*;

pers_1.addEventListener(MouseEvent.CLICK, showMovie);
pers_2.addEventListener(MouseEvent.CLICK, showMovie);
pers_3.addEventListener(MouseEvent.CLICK, showMovie);
pers_4.addEventListener(MouseEvent.CLICK, showMovie);
pers_5.addEventListener(MouseEvent.CLICK, showMovie);

// buttons' labels
pers_1.txt.text = "Historical Perspective";
pers_2.txt.text = "Behavioral Perspective";
pers_3.txt.text = "Symbolic Perspective";
pers_4.txt.text = "Structural Perspective";
pers_5.txt.text = "Normative Perspective";

// creating tweeing
movie_1.visible=false;
movie_2.visible=false;
movie_3.visible=false;
movie_4.visible=false;
movie_5.visible=false;

function showMovie(Event:MouseEvent): void
{ switch(Event.currentTarget.name){
  case "pers_1":
  movie_1.x +=3; if (movie_1.x <=130) {movie_1.visible=true}
  var panel1:Tween = new Tween(movie_1, "x", Elastic.easeOut, 100, 245, 4, true);
  movie_2.visible=false; movie_3.visible=false; movie_4.visible=false; movie_5.visible=false;
  break;
 
  case "pers_2":
  movie_2.x +=3; if (movie_2.x <=130) {movie_2.visible=true}
  var panel2:Tween = new Tween(movie_2, "x", Elastic.easeOut, 150, 130, 4, true);
  movie_1.visible=false; movie_3.visible=false; movie_4.visible=false; movie_5.visible=false;
  break;
 
  case "pers_3":
  movie_3.x +=3; if (movie_3.x <=130) {movie_3.visible=true}
  var panel3:Tween = new Tween(movie_3, "x", Elastic.easeOut, 100, 140, 3, true);
  movie_1.visible=false; movie_2.visible=false; movie_4.visible=false; movie_5.visible=false;
  break;
 
  case "pers_4":
  movie_4.x +=3; if (movie_4.x <=130) {movie_4.visible=true}
  var panel4:Tween = new Tween(movie_4, "x", Elastic.easeOut, 100, 130, 3, true);
  movie_1.visible=false; movie_2.visible=false; movie_3.visible=false; movie_5.visible=false;
  break;
 
 
  case "pers_5":
  movie_5.x +=3; if (movie_5.x <=130) {movie_5.visible=true}
  var panel5:Tween = new Tween(movie_5, "x", Elastic.easeOut, 120, 245, 3, true);
  movie_1.visible=false; movie_2.visible=false; movie_3.visible=false; movie_4.visible=false;
  break;
 
}//switch

}//function

Please suggest ways to correct this problem,

German