title: iOS Tapku library calendar is black on some devices (TKCalendarMonthTableViewController)
body: <p>I'm using the Tapku library to show a calendar of events, it's showing correctly on my device (iPhone 5 with iOS 6.1.3), but on some other devices or the simulator, the calendar is black (check the screenshots) </p>
  
  <p><img src="https://i.stack.imgur.com/n4Xjl.png" alt="this is correct"></p>
  
  <p><img src="https://i.stack.imgur.com/YcS9O.jpg" alt="this is incorrect"></p>
  
  <p>The calendar is an object of TKCalendarMonthTableViewController </p>
  
  <p>Any idea why it's not showing correctly everywhere? </p>
  
  <p>Thanks</p>