Weird, unexpected, inaccurate history

This page says I removed many images from a pool, and added many other images to it, simultaneously, at 2011-09-24 10:00. But I don't remember doing anything like that, and it does not seem to have changed anything in the pool.

http://danbooru.donmai.us/pool/history/4191

The weirdness was caused by some of the posts having negative numbers in the ordering.

There's a 2 year old trac about this.