Joystick position

Hi, can someone please tell me why when I use the below code the joystick is at the far right side of the screen in all aspects but when compiled it is just off centre.

 var radius : float; //Radius of movement
 var deadZoneRadius : float; //Radius of dead zone within which the input value returned is 0
 
 private var gui : GUITexture; //Reference to the GUITexture component of this gameObject
 private var startingPosition : Vector2; //Starting position of this gui
 private var startingScreenCenter : Vector2; //Starting center screen position of this gui
 private var touchIndex : int = -1; //Index of the iPhone touch that hits this gui
 
 private var otherJoysticks : Joystick[];
 
 function Awake() {
 
     gui = GetComponent("GUITexture"); //Gather the reference for the GUITexture component
 
         gui.pixelInset.x = Screen.width - gui.pixelInset.width - 30;
         gui.pixelInset.y = Screen.height - Screen.height + 30;
         
         Debug.Log(gui.pixelInset.x + "  " + gui.pixelInset.y);
 
 
     //Calculate starting position and starting screen center
     startingPosition = Vector2(gui.pixelInset.x, gui.pixelInset.y);
     startingScreenCenter = Vector2(gui.pixelInset.x + gui.pixelInset.width * 0.5, gui.pixelInset.y + gui.pixelInset.height * 0.5);
     
     otherJoysticks = FindObjectsOfType(Joystick); //Gather references to all joysticks in scene
 }
 
 function Update () {
     var touch : Touch;
     if(touchIndex == -1) { //If a touch has not hit this gui since last time a touch was ended/canceled
         for(var i=0; i<Input.touchCount; i++) { //Go through all current touches
             touch = Input.GetTouch(i); //Get touch
             if(gui.HitTest(touch.position)) { //If this touch hits this gui
                 touchIndex = i; //Set touch index to this touch
                 for(var j=0; j<otherJoysticks.Length; j++) {
                     if(otherJoysticks[j] != this)
                         otherJoysticks[j].TouchTaken(touchIndex);
                 }
                 break; //We've found our touch so break out of the loop
             }
         }
     }
     if(touchIndex != -1 && touchIndex < Input.touchCount) { //If a touch has hit this gui and its index does not point to an invalid element in the current touch array
         touch = Input.GetTouch(touchIndex); //Get touch
         if(touch.phase == TouchPhase.Began || touch.phase == TouchPhase.Moved) { //If touch phase is Began or Moved
             var difference : Vector2 = touch.position - startingScreenCenter; //Calculate the difference between current touch position and the starting center screen position of this gui
             if(difference.magnitude > radius) { //If the length of the difference vector is greater than the radius of movement
                 //Limit the distance of the difference vector so that input stays within the [-1..1] range
                 var radians = Mathf.Atan2(difference.y, difference.x);
                 difference.x = Mathf.Cos(radians) * radius;
                 difference.y = Mathf.Sin(radians) * radius;
             }
             //Set the pixel inset of the GUITexture to show the movement of the joystick
             gui.pixelInset.x = difference.x + startingPosition.x;
             gui.pixelInset.y = difference.y + startingPosition.y;
         } else if(touch.phase == TouchPhase.Canceled || touch.phase == TouchPhase.Ended) { //If touch phase is Ended or Canceled
             touchIndex = -1; //Reset touch index to an invalid number
             //Reset the pixel inset of the GUITexture to its starting position
             gui.pixelInset.x = startingPosition.x;
             gui.pixelInset.y = startingPosition.y;
         }
     } else {
         touchIndex = -1; //Reset touch index to an invalid number
         //Reset the pixel inset of the GUITexture to its starting position
         gui.pixelInset.x = startingPosition.x;
         gui.pixelInset.y = startingPosition.y;
     }
 }
 
 //Returns the current input axis vector
 function GetAxis() {
     var axis = Vector3(gui.pixelInset.x, gui.pixelInset.y, 0) - startingPosition;
     return (axis.magnitude < deadZoneRadius) ? Vector3.zero : axis/radius;
 }
 
 //Returns whether a given touch position is contained within this gui
 function ContainsPosition(touchPosition : Vector2) {
     return gui.HitTest(touchPosition);
 }
 
 //Called by other Joysticks when a touch has been taken
 function TouchTaken(takenTouchIndex : int) {
     if(touchIndex == takenTouchIndex) { //If the touch that another Joystick took has the same index as this Joystick's touch
         touchIndex = -1; //Let the touch go
         //Reset the pixel inset of the GUITexture to its starting position
         gui.pixelInset.x = startingPosition.x;
         gui.pixelInset.y = startingPosition.y;
     }
 }