UICollectionView Footer

in your code why you are dequeing a header view and adding the footer to it ?

the normal implementation of this method is :

- (UICollectionReusableView *)collectionView:(UICollectionView *)theCollectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)theIndexPath 
{

   UICollectionReusableView *theView;

   if(kind == UICollectionElementKindSectionHeader)
   {
      theView = [theCollectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"header" forIndexPath:theIndexPath];
   } else {
      theView = [theCollectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:@"footer" forIndexPath:theIndexPath];
   }

   return theView;
}