title: UICollectionView do not reuse cells
body: <p>I am having trouble with reuse cells and <code>UICollectionView</code> on iOS 7. My code works fine on iOS 6 but in iOS 7 it does not reuse the cell after calling <code>dequeueReusableCellWithReuseIdentifier</code> (do not call <code>prepareForReuse</code>).</p>
  
  <p>Even this code <a href="https://developer.apple.com/library/ios/samplecode/CollectionView-Simple/Introduction/Intro.html#//apple_ref/doc/uid/DTS40012860" rel="nofollow">https://developer.apple.com/library/ios/samplecode/CollectionView-Simple/Introduction/Intro.html#//apple_ref/doc/uid/DTS40012860</a> does not reuse cell on iOS7 (but works well on iOS6), on every <code>dequeueReusableCellWithReuseIdentifier</code> it creates a new cell and deallocates the old one. Is there some new stuff that prevents cells to be reused?</p>
  
  <p>My cells are big enough that they it is very inefficient to not reuse them. I've notice lag on iOS 7, but not on iOS 6, because they are not being reused in iOS 7.</p>