I tried out Transmission 1.7.2 from the Development repo for Diablo.
Strangely it works as it's seeding but I'm not sure how because when I look at the torrent site for the torrent I'm seeding I'm not listed there as a peer at all so the tracker is not registering me as being connected to the swarm. Since it's a private torrent site it's a fair bet that my upload isn't being counted either.
Alas while Transmission 1.34 works well on Diablo there's very few private torrent sites that still allow it.