On to the next problem with updating to Omeka 1.3!
The map itself no longer shows up in either the public or admin view. I uploaded the most recent version of the plugin, but it does not seem to be working. At first, it still indicated the number of plotted items (188) with a blank box where the map usually is. I foolishly thought that I could uninstall and reinstall the plugin, and now all my geolocation data is gone. It's not the end of the world, but even after I reinstalled the plugin, I still don't have my map.
I configured the geolocation plugin with the latitude and longitude, the level, and such, just like last time.