Facebook has recently changed the way they deliver checkin/location data. Instead of sending one location for each place, they’re now sending multiple checkins with duplicate coordinates (one for every photo you uploaded for example). This has caused our import process to break in some cases.
If you’re creating a map from your Facebook checkins and the places aren’t displaying in the map, try the import again and uncheck any duplicate places in the list on the import page (leave the first one checked). Then create your map and the import should work correctly.