title: UICollectionView working on iOS7 but not on iOS6
body: <p>My <code>UICollectionView</code> cells don't get displayed on iOS6, because my delegate method <code>cellForItemAtIndexPath</code> doesn't get called. I suspect because of this warning:</p>
  
  <pre><code> the behavior of the UICollectionViewFlowLayout is not defined because:
   the item height must be less that the height of the `UICollectionView`
   minus the section inset's top and bottom values.
  </code></pre>
  
  <p>I don't get the warning on iOS7, and all the cells display correctly there too.</p>
  
  <p>I've set my <code>collectionView</code> frame to height 270 in the <code>.xib</code> and there are no insets defined.
  I've set my cell height to 270 in the <code>.xib</code>.
  I can print out my <code>collectionView</code> frame at runtime and it's 271.</p>
  
  <p>Also, my <code>collectionview</code> is actually inside a custom <code>tableview</code> cell.</p>
  
  <p>Any ideas?
  Thanks!</p>