saveScene and loadScene - How do I add script control?

I create a scene with two objects. Both objects have the following
properties set (in addition to others) in their datablocks:

UseMouseEvents = "1";
CollisionResponseMode = "BOUNCE";

Object1 is immovable. Object2 bounces up and down on the immovable object.

With each collision, a function,Object2Class::onCollision(%this) causes a sound to be played (alxPlay).

Also, both objects can be deleted with the click of a mouse using a function like this:

function Object1Class::onMouseDown( %this, %mod, %worldPos, %mouseClicks ){%this.safeDelete();}

I run this function:

function Save()sceneWindow2D.getSceneGraph().saveScene("~/state.scn");}

Then I run this function:

function Load(){sceneWindow2D.getSceneGraph().loadScene("~/state.scn");}

Visually, the two objects behave just as they did. However, the object
collision no longer triggers an audio event, and neither object can be
deleted by a mouse click.

How might the objects retain their scripted properties using saveScene and loadScene? If this isn't possible, what do I need to be looking at?