Gettysburg '77 orphan pieces

I started a game of Gettysburg '77 (with myself) in Vassal 3.1.7 (I think it was). After upgrading Vassal to version 3.1.8 (and later to 3.1.9), my saved game has spurious pieces laying around. These pieces aren’t selectable.

Anybody know what’s wrong or, more to the point, what I can do about it?

Thank you developers! Upgrading to Vassal version 3.1.10 seems to have fixed this problem! When I open the saved game that was having this problem, the spurious pieces show up for an instant and then they disappear.
Thanks again!