C# Drag rotation code crashing unity with no errors.

Hey,

I'm trying to implement the drag rotation script from this thread: http://forum.unity3d.com/threads/13440-Physics-Input-Questions in C# rather than java, but every time I try to play it unity crashes as soon as I click on my sphere. There are no compiling errors, no error messages, it just freezes... Tried a bunch of stuff, but I can't seem to find what's crashing unity. Maybe I just need to take my eyes off the code for a little bit. In the meantime, if anyone has any ideas and could lend a hand I'd really appreciate the help.

Here's my code:

 `   using UnityEngine;
     using System.Collections;
     using System.Collections.Generic;
     
     //Make sure there is always a rigidbody
     [RequireComponent (typeof (Rigidbody))]
     [RequireComponent (typeof (SphereCollider))]
     
     public class Planet_Controls : MonoBehaviour {
         
         // Key press vars
         public float fRotationSpeed = 100.0F;
         public float fFriction = 1;
         public float fInterpolation = 1;
         
         // Drag rotate vars
         public int iNumberAverages = 3;
         private Quaternion qOriginalRot;
         private Quaternion qOffsetRot;
         
     
         
         // Use this for initialization
         void Start () {
         
         }
         
         void Awake() {
             iNumberAverages = Mathf.Clamp(iNumberAverages,1,iNumberAverages);
         }
         
         void OnMouseDown() {
             RaycastHit hit;
             Vector3 dir;
             
             //Stop spinning
             rigidbody.angularVelocity = Vector3.zero;
             
             //Record Initial Vars
             if(Physics.Raycast (Camera.main.ScreenPointToRay(Input.mousePosition),out hit)){
                 qOriginalRot = transform.rotation;
                 dir = hit.point - transform.position;
                 qOffsetRot = Quaternion.Inverse (Quaternion.LookRotation(dir));
                 Spin(dir);
             }
         }
         
         void Spin (Vector3 dir) {
             RaycastHit hit;
             List<Vector3> previousDirList;
             Vector3 currentDir = dir;
             
             previousDirList = new List<Vector3>();
             
             //init previousdir list
             for (int i = 0; i < iNumberAverages; i++){
                 previousDirList.Add(currentDir);
             }    
             //Make the object rotate with the cursor while we are grabbing it
             while (Input.GetButton("Interact") && Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition),out hit)) {
                 //Remove 1st element of array
                 previousDirList.RemoveAt(0);
                 
                 //Add currentdir to the end
                 previousDirList.Add(currentDir);
                 currentDir = hit.point - transform.position;
                 transform.rotation = Quaternion.LookRotation (currentDir) * qOffsetRot * qOriginalRot;
             }
             
             //User let go of the mouse, so let it spin on its own
             Vector3 avgPreviousDir = Vector3.zero;
             
             for (int i = 0; i < iNumberAverages; i++) {
                 avgPreviousDir += previousDirList[i];
             }
             
             avgPreviousDir /= iNumberAverages;
             
             Kick(currentDir,avgPreviousDir);
         }
         
         void Kick (Vector3 r2, Vector3 r1){
             Vector3 linearVelocity;
                     
             //Calculate the angular velocity: omega = r x v / r^2
             linearVelocity = (r2-r1) / Time.deltaTime;
             
             rigidbody.angularVelocity = Vector3.Cross (r2, linearVelocity) / r2.sqrMagnitude;
         }
         
         // Update is called once per frame
         void Update () {
             //Key press rotation system
                 //Grab inputs
                 float xrot = Input.GetAxis("XRot")*fRotationSpeed;
                 float yrot = Input.GetAxis("YRot")*fRotationSpeed;
                 float zrot = Input.GetAxis("ZRot")*fRotationSpeed;
                 //Keep it rotating every frame
                 xrot *= Time.deltaTime;
                 yrot *= Time.deltaTime;
                 zrot *= Time.deltaTime;
                 //Apply rotation to object
                 transform.Rotate(xrot,yrot,zrot);
         }
     }`