I tried to upgrade EM to 4.0.83 (from 4.0.6), but discovered these (related?) issues:
The date picker dissappeared, making it impossible to create new events.
The default Location were inserted regardless of what you inserted in the new event.
Inserting the Event time did not work as usual (needed to be inserted manually - not the usual "tab-feature" betw. hour, minutes and PM/AM.
I downgraded to 4.0.6 again and all is OK