When I improved the 'apng' file parsing the other week, there was a mistake in how I hooked it up and not all the file metadata was being propagated to the database. A couple of users got some weird '1 frame' apngs as a result. I have fixed this problem, and improved the parsing to deal with more sorts of apngs, and scheduled a complete rescan of all your apngs to get some nicer 'number of frames' counts.
In a related thing, a user sent in a way to get some cool metadata from 'clip' files. These now get resolution and a rough thumbnail. I have scheduled all your clip files, if you have any, to update too.