I'm having an issue, 

I have a simple UICollectionView with a static 200 cells that load images from Flickr.

my CellForItemAtIndexPath looks like this:

```
- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    UICollectionViewCell *cell = [cv dequeueReusableCellWithReuseIdentifier:@"FlickrCell" forIndexPath:indexPath];
    cell.backgroundColor = [self generateRandomUIColor];

    if(![[cell.subviews objectAtIndex:0] isKindOfClass:[PFImageView class]])
    {
        NSURL *staticPhotoURL = [self.context photoSourceURLFromDictionary:[self.photos objectAtIndex:indexPath.row] size:OFFlickrSmallSize];
        PFImageView *imageView = [[PFImageView alloc] initWithFrame:CGRectMake(0, 0, cell.frame.size.height, cell.frame.size.width) andImageURL:staticPhotoURL andOwningCell:cell];
        [cell addSubview:imageView];
    }
    return cell;
}

```

PFImageView is a subclass of `UIImageView` that loads a Flickr photo URL on a background thread and then updates it's own image on the main thread - this works fine.

The logic is really simple - I create a cell if there isn't one dequeueable.

If the cell (which I'm expecting to be dequeued and already have a PFImageView) **doesn't** have a PFImageView, I alloc and init an imageView for the cell and add it as a subview of the cell.

Thus I expect **if the cell has been dequeued it should already have a PFImageView as a subview and as we should not get into the if statement to create a new imageView and kick off a new photo download request** 

Instead what I see is that the cells at the top and bottom of the UICollectionView that 'go off screen' momentarily - when they come back on screen they are not being reused and seemingly a new cell is created and the picture refreshed.

1) How can I achieve a static image once the cell has been created (i.e. not refreshing when the cell goes slightly off screen.

2) Why are the cells not being reused?

Many thanks for your time.

John