My previous attempt to submit this bug report was closed as "not a bug" without explanation. It is a bug, so I am resubmitting with steps to reproduce. The problem, as described in the summary above, is that when you click the Motion Curve button in the Elastic Motion Editor and try to select a different motion curve for an elastic motion, the new curve is not applied. Example:

1. Go to Content Manager -> Prop and add any prop to the scene.
2. Go to Content Manager -> Elastic Motion and apply an elastic motion.
3. Double-click the elastic motion on the timeline to open the Elastic Motion Editor.
4. Click the Motion Curve button and try to choose a new motion curve.
5. Note that the new curve does NOT get applied (in my trial version of CA4).