Bob, as we discussed last night, you can test the gluing properties of your components after you've changed them by inserting a new instance of the component in your model. Also, as I tried to tell you before our connection was cut, I don't think gluing is going to solve the "instability" issue you've been experiencing. That's not what SketchUp's gluing is for.
Gluing is used as an aid for positioning components on faces but it doesn't prevent them from being moved after they've been placed. For that you need to lock them or at least avoid them with the Move and/or Rotate tools.
As I told you last night when we were chatting, I would like to help you sort out what is happening in your drawing process that causes what you describe as instability. I'm convinced there's something fairly fundamental that can be fixed.