It sounds like you do not have the correct port forwarding settings configured on your network. The other problem with this is that your torrent client seems to use a random port every time you start it up. This can become problematic….
See... In order to get optimal upload traffic, even when you're not leeching the torrent or are the only seeder, you need to ensure that the port that your torrent client uses is forwarded to your computer, both in TCP and UDP. To do this properly and securely, you need to first turn off the random port option, so that you can forward just ONE port to use with your torrents. Once this is done and incoming connections can be properly forwarded through to your computer, you should notice a HUGE difference in the results.