GWT Calendar API 3 CalendarEntryPoint.java insertEvent returns Bad Request Cntx

[Robo]

CalendarEntryPoint.java works except for the insertEvent which is giving me a Bad Request Cntx as it is presented in the example.
onModuleLoad, login, and getCalendarId work as expected, but the insertEvent returns

Bad Request Cntx: com.google.api.gwt.services.calendar.shared.Calendar_EventsContextImpl@40

The event in the example when printed as event.toString returns:
com.google.api.gwt.services.calendar.shared.model.EventAutoBean_com_google_web_bindery_requestfactory_shared_impl_EntityProxyCategory_com_google_web_bindery_requestfactory_shared_impl_ValueProxyCategory_com_google_web_bindery_requestfactory_shared_impl_BaseProxyCategory$2@9386df6b

Please, Please help me here.

Thanks