Android: Fragment in ViewPager not restored after popBackStack

just change getActivity().getSupportFragmentManager() to getChildFragmentManager() when you init viewPagerAdapter

viewPager = (HeightWrappingViewPager) view.findViewById(R.id.viewpager);
viewPagerAdapter = new CheckListViewPagerAdapter(getChildFragmentManager()); //getActivity().getSupportFragmentManager()
viewPager.setAdapter(viewPagerAdapter);

ref: http://stackoverflow.com/questions/13379194/how-to-add-a-fragment-inside-a-viewpager-using-nested-fragment-android-4-2
https://code.google.com/p/android/issues/detail?id=55068