The clusterpurge.php script does not delete expired items that are in the scope 'images' on the 'ezdfsfile' table; it only clears items for the scope 'image'.
1. Configure eZP 5.2 in DFS cluster mode;
2. Create an object with an image;
3. Publish some versions;
4. Query 'ezdfsfile' table, and make a note of what records exist for "scope=images" and "expired=1". The following query should suffice:
5. Run, from the command line:
Got "Purging expired items:" message, and could see, by querying 'ezdfsfile' table again, that expired records are still there.