Since I began using a router, my torrents became really slow and I had no idea why. I had to endure a couple of weeks of painfully slow downloads until I finally googled it to find my answers. I followed them step by step and it sorta worked for me, though my max speeds never reach over 60kB/s in my lifetime. Here’s some help if you have the same router-torrent issue.

Basic instructions
Similar instructions
Firewall instructions and for Azureus users
I recommend using Azureus, it’s more powerful. So make the switch now.
Help for Windows XP SP2 users
Speed up your torrents (Router or no router)

In any case, if you’re using Streamyx, it’s bound to act up eventually so don’t panic if your downloads suddenly cap at 0kB/s. No offense, TMNet.