Is there a way to lock the local position of a game object?

I have a sphere as my player, and I am scripting it so that when I press a button, a game object becomes a child to my player object. I don't know what's going on, but I just can not get the child to lock it's relative position. I just want it floating in space beside my sphere, but nothing seems to work. The child just wanders off into empty space, slowly twirling around, and if I rotate about the vertical axis, it gradually gets thrown further off, as if affected by centrifugal force.

I've tried things like transform.localPosition = Vector3.zero;, and transform.position = player.position + offset;, and even borrowing script from the SmoothFollow camera script, but just nothing is working. I just want my game object to behave in movement as if it's a camera, can anyone help?

This is my script (in js):

[code]

 #pragma strict
 
 var player : Transform; 
 var attachToObject = GameObject;
 var offset : Vector3;
 
 function Start () 
     {
         player = GameObject.FindWithTag("Player").transform;
     }
 
 function Update () {
 
 
     if (Input.GetKeyDown(KeyCode.Space))
     {
         transform.parent = GameObject.FindWithTag("Player").transform;
         rigidbody.useGravity = false;
         transform.position = player.position + offset;
     }
 }

[/code]

(Sorry, I am trying to format this to show the code correctly too...)