Hi Stefan,
Yes, it worked perfectly with 1.5.1. Also I posted an issue with a suggestion to improve load time significantly when loading lots of events.
Background - I tried with 60+ events and it took 2-3 seconds to load it locally. By batching the entries and only doing one getElement().callFunction() the load time drops to almost nothing.
The code is there: https://github.com/stefanuebe/vaadin_fullcalendar/issues/9
Thanks for the great work.