Are these problems are related to a NGUI change (update)

I have a code from a tutorial on youtube (unitycookie). Somebody helped me to fix a lot of mystiping in the code but I som strange problems now that I think are related to NGUI. I am using Unity 4.0.7f pro and NGUI 2.6.4 full. Here is my code:

 #pragma strict
 
 var buildPanelOpen : boolean = false;
 var buildPanelTweener : TweenPosition;
 var buildPanelArrowTweener : TweenRotation;
 
 var placementPlanesRoot : Transform;
 var hoverMat : Material;
 private var originalMat : Material;
 private var lastHitObj : GameObject;
 
 var onColor : Color;
 var offColor : Color;
 var allStructures : GameObject[];
 var buildBtnGraphics : UISlicedSprite;
 private var structureIndex : int =0;
 
 function Start()
 {
     structureIndex = 0;
     UpdateGUI();
 }
 
 function Update ()
 {
     if(buildPanelOpen)
     {
         var ray = Camera.main.ScreenPointToRay (Input.mousePosition);
         var hit : RayCastHit;
         if(Physics.Raycast (ray, hit, 1000, placementLayerMask))
         {
             if(lastHitObj)
             {
                 lastHitObj.renderer.material = originalMat;
             }
             lastHitObj = hit.collider.gameObject;
             originalMat = lastHitObj.renderer.material;
             lastHitObj.renderer.material = hoverMat;
         }
         else
         {
             if(lastHitObj)
             {
                 lastHitObj.renderer.material = originalMat;
                 lastHitObj = null;
             }
         }
         if(Input.GetMouseButtonDown(0)&&lastHitObj)
         {
             if(lastHitObj.tag == "PlacementPlane_Open")
             {
                 var newStructure : GameObject = Instantiate(allStructures[structureIndex], lastHitObj.transform.position, Quaternion.identity);
                 newStructure.transform.localEulerAngles.y = (RandomRange(0,360));
                 lastHitObj.tag == "PlacementPlane_Taken";
             }
         }
     }
 }
 
 function UpdateGUI()
 {
     for(var theBtnGraphic : UISlicedSprite in buildBtnGraphics)
     {
         theBtnGraphic.color = offColor;
     }
     buildBtnGraphics[structureIndex].color == onColor;
 }
 
 function SetBuildChoice(btnObj : GameObject)
 {
     var btnName : String = btnObj.name;
     if(btnName == "Btn_Cannon")
     {
         structureIndex = 0;
     }
     else if(btnName == "Btn_Missile")
     {
         structureIndex = 1;
     }
     else if(btnName == "Btn_Mine")
     {
         structureIndex = 2;
     }
     UpdateGUI();
 }
 
 function ToggleBuildPanel()
 {
     if(buildPanelOpen)
     {
         for(var thePlane : Transform in placementPlanesRoot)
         {
             thePlane.gameObject.renderer.enabled = false;
         }
         buildPanelTweener.Play(false);
         buildPanelArrowTweener.Play(false);
         buildPanelOpen = false;
     }
     else
     {
         for(var thePlane : Transform in placementPlanesRoot)
         {
             thePlane.gameObject.renderer.enabled = true;
         }
         buildPanelTweener.Play(true);
         buildPanelArrowTweener.Play(true);
         buildPanelOpen = true;
     }
 }

And the errors that are showing:

Please help! If this problem is related to NGUI what I need to do with the code to get it working.