Multiple maps appear when moving cursor

Using Vassal 3.7.7. Playing On to Richmond 2. Many times when I move the cursor, the map replicates a section of the map blocking the map on which we are playing. It will create several images of a portion of the map. So far, the only way I have managed to clear the extraneous maps is to minimize and expand Vassal. However, the problem resumes shortly thereafter.

Are you using Windows? If so, this may be your problem:"Tearing"_on_maps,_Corrupted_Graphics,_or_Map_Not_Fully_Updating

If not, please state what operating system you’re using.