As many beta testers know, the calendar in iOS 5b2 is pretty much unusable. I'm a calendar warrior and use it frequently; these are the three bugs I've discovered thus far. I have not seen them grouped together in one place yet, so I hope this helps other beta users. Calendar hangs indefinately in Month View. All calendar accounts must be turned off and on again to restore calendar functionality. "Availability" option is missing for new appointments.