[Plugin: Events Calendar] Date picker doesn't work

I just upgraded to 4.0.82 and I now can’t add events.

The date picker doesn’t work, and when I try to set the date manually (using the same format, e.g. “06/16/2011”.

I get this message:

Missing fields: event_start_date.
Dates must have correct formatting. Please use the date picker provided.

http://wordpress.org/extend/plugins/events-calendar/