Click "Details" on one of your downloads. You will see in there something listing the "Tracker URL." It would be in the form of:
http://tracker.site.com:6969/announce
What does it for the tracker's port number which is after the site's name ("tracker.site.com") after the colon (":") and before the forward slash and "announce" ("/announce") ? (For example, the above example's port number is "6969")
Does that number say "6969" or does it say something else? If the tracker URL looks like this:
http://tracker.site.com/announce
where it shows no ":" and no number, then it is using port 80.