stopTouchDrag problem

thank you

i tried to change to TOUCH_OUT but it doesnt work

this is part of my my code:

if i have only 8 big squares on stage it works ok. the problem is when there are 36  targets on stage (squares are small).

i remind you than when simulating it works perfect - problem is on iphone device.

function end_s(event:TouchEvent):void

{

                    event.target.stopTouchDrag(event.touchPointID);

                    var targets_16;

                    var obj_16 = event.target;

                    event.target.stopTouchDrag(event.touchPointID);

                    targets_16=(obj_16.dropTarget.parent)

                    //if hits the free squares - sticks to them

                    if(obj_16.hitTestObject(ma1)||obj_16.hitTestObject(ma4)||obj_16.hitTestObject(ma5)||obj_16.hitTestObject(ma6)

               ||obj_16.hitTestObject(mb1)||obj_16.hitTestObject(mb2)||obj_16.hitTestObject(mb3)||obj_16.hitTestObject(mb4)||obj_16.hitTestObject(mb6)

               ||obj_16.hitTestObject(mc1)||obj_16.hitTestObject(mc5)||obj_16.hitTestObject(mc6)

               ||obj_16.hitTestObject(md2)|obj_16.hitTestObject(md4)

                     ||obj_16.hitTestObject(me2)||obj_16.hitTestObject(me3)||obj_16.hitTestObject(me4)

               ||obj_16.hitTestObject(mf2)||obj_16.hitTestObject(mf3)||obj_16.hitTestObject(mf4)||obj_16.hitTestObject(mf6))

                    {

                      obj_16.x=targets_16.x

                    obj_16.y=targets_16.y

                      my_sound_s.play();

                      trace(s_placex);

             }

             else{

                        obj_16.x=s_placex;

                              obj_16.y=760;

                                 trace(targets_16.name);

            }