I've been downloading a torrent for the past 3 days and it has been downloading for a steady 70 kbps. There were also other torrents downloading. About 2-3 torrents were downloading. When I opened my computer today, all the torrents were dead. I had to call for other trackers by btreannouncer. Now, it's alive again but it's downloading at less than 20 kbps. What happened?