That's the thing, the torrent wasn't downloading at all. It said on the tracking site that there were like 30 seeds and 3 leechers, but when I tried to download it, there were magically about 20 leechers and absolutely no seeds.
You just have to wait. Just because the tracker says "x seeds" doesn't mean that there are that many
currently available. A lot of them won't want to connect with you until your ratio is better, too.
And 30 seeds and 3 leechers isn't really enough to get a good rate, anyway.
And to add to Anyways' post: leechers still upload. You upload as you download. This is how the network works. Large files get split up into small chunks, and your computer gets those chunks from various machines in the crowd. Most of your download bandwidth isn't going to be from the seeders; it's coming from the leechers (assuming that there are many more leechers than seeders, as there usually is on a mature, but not old torrent). Seeders mainly fill in the gaps.