Touch are laggy on ipod touch(4th gen.)

Hi. I am currently using gameObjects for user interface in my game. The are childed to main camera and i use this code for detecting touches.

function Update() { if(Input.touchCount > 0) { for (var i = 0; i < Input.touchCount; ++i) {

     var xTouch : Touch = Input.GetTouch(i);
     var xRay : Ray = Camera.main.ScreenPointToRay (xTouch.position);
     var xHit : RaycastHit ;
     
     if(Physics.Raycast (xRay, xHit, 25) )
     {
         if(xHit.collider.tag == "bLeft" && !isPaused)
         {
            rotLeft = true ;
            rotRight = false;
            
         }
                // and there is more but same as above
           }

}

This worked for me until some of new level in my game touches are very laggy on my iPod Touch(4th gen.) Booth with unity remote and builded version. Should i use guitexture for user interface or this lag occur because of something else. By the way laggy level has only 8-10 draw calls, other levels has 20-25 draw calls.