Torrent Transfer Balancing

For some reason, my torrent client (KTorrent) has crappy download speeds but very high upload speeds. I have set a share ratio limit and an upload speed limit, both of which don't appear to be working. Is there some way I can configure the client to be more fair or something at the network level I can do?

Don't bother with comments like "Use a different client" because they'll be ignored.

>>13
I use NAT and I have 6881/tcp and 6881/udp both open. It seemed to work ok before. Wouldn't an ISP outright block those ports rather than slow them down?