I just had the same experience. The plugin has been great, but this is a real pickle. Stupidly, I did not have a backup. I knew I was going to have to re-do my css modifications, but this is worse. I can’t use the calendar view.
One quick cure (tho far from ideal): switch to event list view, and you don’t get the problem, but there are other issues:
– no lightbox with the additional info and link added with the event-list view
– two events are showing up in the list on the site, but they are not in the calendar in admin and cannot be edited.