title: iOS 7 UISearchDisplayController search bar disappears
body: <p>I was recently updating my app and came across this issue. When i start typing in the search bar the search bar disappears and i can only see the table view. I can still keep on typing and the table view gets updated but i cannot see the search bar. 
  Same settings works fine on iOS &lt; 7</p>
  
  <p>Any idea why this is happening ? </p>
  
  <p><img src="https://i.stack.imgur.com/Hv4F3.png" alt="Step 1">
  <img src="https://i.stack.imgur.com/W9pH2.png" alt="Step 2">
  <img src="https://i.stack.imgur.com/Xng4R.png" alt="Step 3"></p>