lost custom maps in upgrade to 3.1.2

I just "upgraded" from 3.1.1 to 3.1.2 basecamp for mac. After doing so, my custom kmz files show in the list in basecamp as custom maps, but they will not show up. I can select the map, and the outlined area is there, but the map has vanished??? They worked fine before the upgrade (literally mins ago). Any ideas?