Planar Reflection Shadow Bug

This question was brought up a few months ago, but there hasn't been an answer:

http://answers.unity3d.com/questions/924520/objects-are-visible-through-terrain.html

I am having the same problem and have narrowed it down to the Planar Reflection script attached to Unity's water4 prefabs.

In the screenshot you can see 2 issues.

1. Shadows ON objects are showing through the terrain

2. Shadows FROM objects are not appearing on the terrain (the grass shows dark areas of shadows from the trees, but no corresponding shadows on the ground)

Any suggestions?