mousePosition returning previous position

I've already submitted a bug report for this problem. After posting in the scripting section awhile back, it appears this is unexpected behavior. Hope its not too much of a problem that I am posting here too. If I can't figure out this problem soon I want to switch ideas since I am running the trial version. I want to get something presentable out before that time runs out.

In this prototype for a Gauntlet-style game, clicking the mouse inside the game causes the player to shoot a fireball towards where the mouse clicked. The problem is that Input.mousePosition is returning the previous position of the mouse where I had clicked "Fire1". If I click "Fire1" a second time in the same position it will then shoot a fireball to the correct position because the previous position was the same.

Code (csharp):

1. var fireball : Transform;
2.  
3. function LateUpdate ()
4. {
5.     if (Input.GetButtonDown ("Fire1"))
6.     {
7.         // Construct a ray from the current mouse coordinates
8.         var rayHit : RaycastHit;
9.         var ray = Camera.main.ScreenPointToRay (Input.mousePosition);
10.        
11.         if (Physics.Raycast (ray, rayHit))
12.         {
13.             // Get the point in space where the ray hit
14.             // Set the y value to that of this object so that its height is equal
15.             var clickPoint = rayHit.point;
16.             clickPoint.y = transform.position.y;
17.        
18.             // Get the normalized ray from this object to the click point
19.             rayHit.point.y = clickPoint.y;
20.             var rayToClickPoint = rayHit.point - transform.position;
21.             rayToClickPoint.Normalize();
22.            
23.             // Create a particle if hit
24.             Instantiate (fireball,transform.position, transform.rotation);
25.            
26.             var fireballScript = fireball.GetComponent(ProjectileScript);
27.             fireballScript.velocity = rayToClickPoint;
28.             fireballScript.speed = 7.0;
29.             fireballScript.lifetime = 3.0;
30.         }
31.     }
32. }

I've tried Update, LateUpdate, and FixedUpdate. They all provide the same results.

I also attached the built project if you want to check out the problem.

Here is a link to the fire post in Scripting: http://forum.unity3d.com/viewtopic.php?t=25568