There are literally dozens of BitTorrent clients. Uninstall it and re-install it and if that doesn't work, uninstall it and try another.
I prefer ABC BitTorrent. Gives you a lot of control over your downloads with a download manager type interface. It also uses random ports between 10000 and 11000 to spoof your ISP so it's not obvious that you're using a Bit Torrent client.
As with any BitTorrent client , you need forward the port range it uses in the port forwarding settings of your router or your download speed will be capped.