title: defaultCalendarForNewEvents failed
body: <p>When I try to call [newEventStore defaultCalendarForNewEvents], it returns an error message says: </p>
  
  <pre><code>[707:907] defaultCalendarForNewEvents failed: Error Domain=EKCADErrorDomain Code=1013 "The operation couldn’t be completed. (EKCADErrorDomain error 1013.)"
  [707:907] Error!Failed to save appointment. Description:Error Domain=EKErrorDomain Code=1 "No calendar has been set." UserInfo=0x1fc679f0 {NSLocalizedDescription=No calendar has been set.}
  </code></pre>
  
  <p>The app runs for a long time. The problem came to me first time. The phone runs IOS6 Beta4. model is iphone 4.
  Is there anyone knows when the defaultCalendarForNewEvents method will get failed? I can not get any useful information from googling.</p>