Unity Quirk

Physic Collider
1) Q: Basic physic Collider not working
     A: Script override collider (etc: Box Collider)
          See http://answers.unity3d.com/questions/16432/why-wont-my-box-collider-collide.html
2)Attach Script for collision into mesh not it's parent (ie:of GameObject type)
   The Script have something
   like below function OnCollisionEnter(col : Collision) declared.
   while mesh have RigidBody Component (ie: with kinematic chcekbox unchecked)
3)Hit UnassignedReferenceException while drag and drop guitext object to script
   Turns out i need to drag and drop guitext object into another gameobject script component.
    I made a mistake of assigning to the Script itself in Asset window instead of
   Script component in Inspector window for Heart game object.