Button not automatically disable

Question

I am extend the button component to be use in repeater loop that will disabled if an mtutorColList arraycollection contain an exist value.

When I click the button, it will disabled and add a value '10011' to mtutorColList, I try to do pagination test to page 2, all button are enabled since there no button contain '10011' but when I go back to page 1 where I couldn't get the button contain '10011' to be disabled.

The dispatch did not called labelHandler.

    package com {
      import flash.events.Event;
      import flash.events.MouseEvent;

      import mx.controls.LinkButton;
      import mx.core.Application;

      public class Btn extends LinkButton{
        public function Btn(){
          super();
          super.enabled = true;
          this.addEventListener(MouseEvent.CLICK, labelHandler);
          this.addEventListener("enableChanged", labelHandler);
        }

        private function labelHandler(event:Event):void{
            trace("Set button disable");
            super.label = "Added";
            super.enabled = false;
            validateNow();
        }

        override public function set enabled(value:Boolean):void {
            if (Application.application.mtutorColList != '' &&  Application.application.increment < Application.application.lop) {
if(Application.application.productsDP[Application.application.increment][1] == Application.application.mtutorColList) {
               super.dispatchEvent(new Event("enableChanged"))
               trace("Disable button");
              } else {
               super.enabled = true;
               trace("Normal button");
              }
             Application.application.increment++;
         }
        }
      }
    }