title: No activity Exception when using viewpager and fragments inside fragments
body: <p>Let me describe my project.</p>
  
  <p>I use actionbarsherlock with SlidingMeno from jfeinstein10 . On my main activity i have this sliding menu with a couple of menu item that open Fragments in container. (the same as basic fragment sample in sliding menu example) In one of those fragments i have view-pager with viewpageindicator. View-pager is tied up to FragmentStatePagerAdapter with my fragments. So i have fragments inside fragments. I use getChildFragmentManager() like suggested in the doc, when using fragments inside fragments. </p>
  
  <p>When i select menu item with fragment that hold view-pager for the first time everything work like it should. But when i select some other menu item and then go back to this view-pager fragment i get this exception. 
  All other fragments don’t have this problem and in stack trace there is no reference to my code.</p>
  
  <p><a href="https://gist.github.com/4502038" rel="noreferrer">https://gist.github.com/4502038</a></p>
  
  <p>Did any one encounter similar problem or have some idea what is going on.</p>
  
  <p>EDIT: If i use getFragmentManager() instead of getChildFragmentManager() even thou i'm in subfragment. I don't get an exception, but one of the fragments inside viewpager doesn't get recreated after i select viewpager fragment for the second time.</p>
  
  <p>I created a project on github so you guys can take a look.
  <a href="https://github.com/pzagor2/TestErrorApp" rel="noreferrer">https://github.com/pzagor2/TestErrorApp</a></p>