Don't worry about the changed torrent filenames on the mirror, the files are the same. I also renamed the formerly directly linked HD version, so if you try to resume the Eurofurence_15_720p.avi file, it won't be found anymore! Rename the file on disk to allow resuming the download.
Furthermore I dumped the bittorrent-tracker in favor of opentracker, as the aforementioned software didn't stop throwing silly errors and ceasing to work for silly reasons again and again, for no discernible cause. If you were having trouble with the tracker in the past, give it another chance, please.

Hopefully there won't be any more trouble with the tracker. Certainly was a learning experience for me.