Can't rotate by touch an object in augmented reality

I need to rotate by touch an object attached to the image target when it appears on screen in a AR project. I have used this script http://www.revelopment.co.uk/tutorials/unitytutorials/73-howtorotateanobjectbytouch in others projects but I don´t know why doesn't work with this one.

I'm using the Vuforia extension for Unity version 1.5.10 in unity 3.5

 > // Revelopment.co.uk // Created by
 > Carlos Revelo // 2011
 > 
 > 
 > 
 > 
 > /********Main Objects***********/
 > 
 > var targetItem : GameObject; var
 > GUICamera : Camera; var ambient :
 > GameObject;
 > 
 > 
 > /********Rotation Variables*********/
 > var rotationRate : float = 1.0;
 > private var wasRotating;
 > 
 > /************Scrolling inertia
 > variables************/ private var
 > scrollPosition : Vector2 =
 > Vector2.zero; private var
 > scrollVelocity : float = 0; private
 > var timeTouchPhaseEnded: float;
 > private var inertiaDuration : float =
 > 0.5f;
 > 
 > private var itemInertiaDuration :
 > float = 1.0f; private var
 > itemTimeTouchPhaseEnded: float;
 > private var rotateVelocityX : float =
 > 0; private var rotateVelocityY : float
 > = 0;
 > 
 > 
 > var hit: RaycastHit;
 > 
 > private var layerMask = (1 <<  8) | (1
 > << 2);
 > 
 > 
 > 
 > function Start() {     layerMask =~
 > layerMask;     }
 > 
 > function FixedUpdate() {          if
 > (Input.touchCount > 0)      {        //    If
 > there are touches...             var theTouch :
 > Touch = Input.GetTouch (0);        //    Cache
 > Touch (0)
 >                          var ray = Camera.main.ScreenPointToRay(theTouch.position);
 >             //var GUIRay =
 > GUICamera.ScreenPointToRay(theTouch.position);
 >             
 >                 
 >              if(Physics.Raycast(ray,hit,50,layerMask))
 >              {    
 > 
 >                                                if(Input.touchCount == 1)
 >                         {
 >                             
 >                             if (theTouch.phase == TouchPhase.Began) 
 >                              {
 >                                  wasRotating = false;    
 >                              }        
 >                              
 >                              if (theTouch.phase == TouchPhase.Moved) 
 >                              {
 >                                   
 >                                  targetItem.transform.Rotate(theTouch.deltaPosition.y
 > * rotationRate, -theTouch.deltaPosition.x * rotationRate,0,Space.World);
 >                                  wasRotating = true;
 >                              }        
 >              
 >                              if (theTouch.phase == TouchPhase.Ended || theTouch.phase ==
 > TouchPhase.Canceled) 
 >                              {
 >                                  if(wasRotating==true)
 >                                  {
 >                                      if(Mathf.Abs(theTouch.deltaPosition.x)
 > >=10)
 >                                      {
 >                                          rotateVelocityX = theTouch.deltaPosition.x /
 > theTouch.deltaTime;
 >                                        }
 >                                        if(Mathf.Abs(theTouch.deltaPosition.y)
 > >=10)
 >                                      {
 >                                          rotateVelocityY = theTouch.deltaPosition.y /
 > theTouch.deltaTime;
 >                                        }    
 >                                  itemTimeTouchPhaseEnded = Time.time;
 >                                  }
 >                                                    }
 >                         }             }
 > 
 > 
 >             
 >                         
 >                  } /******************** Inertia code ******************************/
 >     if(Input.touchCount == 0 )
 >     {
 >                 if(scrollVelocity != 0.0)
 >              {
 >                  //slowing down
 >                  var t : float = (Time.time - timeTouchPhaseEnded) / inertiaDuration;
 >                  var frameVelocity : float = Mathf.Lerp(scrollVelocity, 0 , t);
 >                          
 >                  scrollPosition.x -= frameVelocity * Time.deltaTime;
 >                          
 >                  if(t >= inertiaDuration)
 >                      scrollVelocity = 0.0f;
 >                          
 >                          
 >              }    
 >          
 >                 if(rotateVelocityX != 0.0f || rotateVelocityY != 0.0f)
 >              {
 >                  //slowing down
 >                  var ty : float = (Time.time - itemTimeTouchPhaseEnded) / itemInertiaDuration;
 >                  var XVelocity : float = Mathf.Lerp(rotateVelocityX, 0 , ty);
 >                  var YVelocity : float = Mathf.Lerp(rotateVelocityY, 0 , ty);     
 >                  
 >                          
 >                  if(ty >= inertiaDuration)
 >                  {
 >                      rotateVelocityX = 0.0f;
 >                      rotateVelocityY = 0.0f;
 >                      
 >                  }    
 >                  targetItem.transform.Rotate(YVelocity*Time.deltaTime
 > * rotationRate, -XVelocity * Time.deltaTime *
 > rotationRate,0,Space.World);        
 >                          
 >              }    
 >         
 >         
 >       }     }