title: iPhone lost all UI transition animation
body: <p>Currently I encounter an issue somehow, the application lost all those artistic UI animation for example, page flipping, alert view popup, action sheet slide up and etc. That means all those UI will show up immediately without any transition animation. It looked very weird. </p>
  
  <p>Firstly, the app will run smoothly until something trigger the issue above, and after that only re-run the app or kill the app will stop the problem.</p>
  
  <p>There is no error message or any clue that I can figure out what could be the reason. Have any one of you guy has encountered similar issue as above? Please share with me how am I able to solve the issue above. Thanks.</p>