Unity Freezes when accessing an Array in a different script GameObject

I create an Array in my "ModularParentScript" (js) like so:

 public var attachPointCount = 0; // Total available attach points on all objects
 public var attachPoints : Array; // The available attach points
 
 function Awake() {
     attachPoints = new Array(); // Create the array to hold the attach points
 }

Then, on a different object, I want to fill that array with the attach points (gameObjects) like so:

 parentScript = parentObject.transform.GetComponent( "ModularParentScript" );

These lines of code run just fine:

 myArray = new Array( parentScript.attachPoints ); // Grab the attach points array
 myArray.Add( theAttachPoint ); // Add an element (if I modified the original array directly it would freeze Unity)

However, this line (when un-commented):

 //parentScript.attachPoints = new Array( myArray ); // Put the modified  array back in the parent

Freezes Unity. So do these:

 //pointsArray = parentScript.attachPoints;
 //pointsArray.Push( theAttachPoint ); // Add attach point to the array
 //parentScript.attachPoints.Add( theAttachPoint ); // Add the point to the list on the parent

It seems any time I try to modify the array in the parent script, it freezes Unity (the kind where you have to Ctrl+Shift+Esc to close it and then reopen). What am I doing wrong here?

Thanks, Simon