I noticed the same thing with this torrent. I've also noticed that it has been happening with other torrents as well. I think the problem may be more generalized.
Watching the torrent activity/traffic for the torrent you mentioned, and also for those that I've noticed with similar problems, I don't agree that it is likely a dial-up user. Rather, I suspect that it is a user who is a) acting on behalf of the performer and using a torrent to generate interest or b) a user who is deliberately throttling seed activity to optimize their download/upload ratio.
