title: App getting hanged while changing orientation
body: <p>i know this is going to be a vague question, but please give a thought to this... 
  I am developing a book reader on ipad and it has many functionalities like highlight, notes etc. and all these functions are woking well. But the problem comes only when i try to rotate my device after implementing any function.. The app is geting struck(or hanged) after changing itz orientation.... </p>
  
  <p>Can anyone tell me why a app usually gets hanged???? Give a thought to this please. Your inputs will help me go a long way.....</p>
  
  <p>Thanks</p>