1. CLick the "show mini-map" button.
2. Click the "Show terrain bonus" button.
3. Mini-map border stays, but with no map features inside at all. Completely see through..
4. Cycle to the next size of the mini map and the mini-map comes back.
5. Reproducible every time.
I will check and make sure, but I believe if I turn on the terrain bonus first and not the mini-map, I do not have this problem.
If this is not the case, I will return and edit this post/