Problem with dynamic text in createtextfield

1 

function anima_banner(XMLObj){
  
  var container:MovieClip = this.__mc.bholder.fotos;
  var viewer:GetImage = new GetImage(container, 137, 98,  0xFFFFFF);
  
  var titulo:MovieClip = this.__mc.bholder.btit_txt
  
  img = XMLObj.childNodes[1].childNodes[4].firstChild.nodeValue;
  trace(img)
  
  t1 = XMLObj.childNodes[1].attributes.titulo_esp
  trace(t1)
  
  titulo.text = "t1"
  
  var my_fmt:TextFormat = titulo.getTextFormat();
  for (var prop in my_fmt) {
   trace(prop+": "+my_fmt[prop]);
  }
  foto = path_fotos+img
  viewer.loadImage(foto);
  
  /*titulo_txt.text = "de"
  trace("t "+tmp.text)
  */
 }
 function crea(XMLObj){
  //trace(XMLObj)
  
  var b_mc = this.__mc.createEmptyMovieClip(("bholder"), this.__mc.getNextHighestDepth());
  b_mc._x = 43
  b_mc._y = 184
   
  var f_mc = b_mc.createEmptyMovieClip(("fotos"), b_mc.getNextHighestDepth());
  f_mc._x = 125
  f_mc._y = 0
  
  var titulo_txt = b_mc.createTextField("btit_txt",b_mc.getNextHighestDepth(),0,0,125,31);
  var my_fmt_ti:TextFormat = new TextFormat();
  my_fmt_ti.color = 0x000000;
  my_fmt_ti.font = "Futura LT Condensed";
  my_fmt_ti.align = "right"
  my_fmt_ti.size = 23
  titulo_txt.embedFonts = true;
  titulo_txt.text = "a"
  titulo_txt.autoSize = false;
  titulo_txt.variable = "titulo";
  titulo_txt.type = "dynamic";
  titulo_txt.setTextFormat(my_fmt_ti);
  
  var texto_txt = b_mc.createTextField("btex_txt",b_mc.getNextHighestDepth(),0,31,125,45);
  var my_fmt_te:TextFormat = new TextFormat();
  my_fmt_te.color = 0x000000;
  my_fmt_te.font = "Futura LT Book";
  my_fmt_te.align = "right"
  my_fmt_te.size = 12
  texto_txt.embedFonts = true;
  texto_txt.text = "b"
  texto_txt.autoSize = false;
  texto_txt.variable = "texto";
  texto_txt.type = "dynamic";
  texto_txt.setTextFormat(my_fmt_te);
  
  var fecha_txt = b_mc.createTextField("bfec_txt"+i,b_mc.getNextHighestDepth(),0,76,125,17);
  var my_fmt_fe:TextFormat = new TextFormat();
  my_fmt_fe.color = 0x000000;
  my_fmt_fe.font = "Futura LT Book";
  my_fmt_fe.align = "right"
  my_fmt_fe.size = 10
  fecha_txt.embedFonts = true;
  fecha_txt.text = "c"
  fecha_txt.autoSize = false;
  fecha_txt.variable = "fecha";
  fecha_txt.type = "dynamic";
  fecha_txt.setTextFormat(my_fmt_fe);
  
  this.anima_banner(XMLObj)
  
 }

well my problem is that i call crea with an xmlobject i create dynamic movieclips and dynamic textfields
if i see that i see it ok

but when i try to chance one of the dynamic textfields i create the text disappear.

i dont know whats happening.

can someone help me.

thanks