Rigidbodies dont push each other out correctly

Hi, I wanted to create procedural dungeon generation explained in this article link text

i created the random room spawning inside of a circle and added them rigidbodies:

 public int count = 50;
     public Vector2 size_range = new Vector2(2, 8);
     public int circle_size = 15;
 
     // Use this for initialization
     void Start () 
     {
         for(int i = 0; i < count; i++)
         {
             int width = Random.Range((int) size_range.x, (int) size_range.y);
             int height = Random.Range((int) size_range.x, (int) size_range.y);
 
             Vector2 pos = transform.position = Random.insideUnitCircle * circle_size;
 
             GameObject clone = GameObject.CreatePrimitive(PrimitiveType.Cube);
 
             clone.transform.localScale = new Vector3(width, 1, height);
             clone.transform.position = new Vector3(pos.x+width/2f, 0, pos.y+height/2f);
 
             clone.AddComponent<Rigidbody>();
             clone.GetComponent<Rigidbody>().drag = 30;
             clone.GetComponent<Rigidbody>().useGravity = false;
             clone.GetComponent<Rigidbody>().constraints = RigidbodyConstraints.FreezeRotation | RigidbodyConstraints.FreezePositionY;
         }

The problem is that the rooms dont push out each other completely and still overlap:

Then when I manually select all objects and change their Collision detection, they start moving, but even though i locked their rotation, they still start rotating, when puhsing each other:

What am i doing wrong? Thanks