After my upgrade to Kubuntu 12.04/Precise Pangolin, I found that while KTorrent worked, it was buggy as right-clicking on torrents did nothing. I blamed this on a configurational mishap during the upgrade and lived with it as I could do perform most operations using the main menu or the toolbar buttons. However, with most sites moving away from
.torrent files and toward magnet links, I found that KTorrent wasn't playing nice with the magnet URIs. According to the KTorrent FAQ, the application is supposed to support magnet links. But all I got when trying to open them via the "Open URL" menu option was an error message.
After some random mucking around, I found that the problem was that I had the wrong version of KTorrent installed. While Precise was supposed to run version 4.1, I was still running 3.3.2 (oslt). IOW, the upgrade had not upgraded my KTorrent installation. I'm not sure if my old version was compiled from the source packages, and that was the reason why it wasn't upgraded. But nevertheless, it was weird not being made aware of it by the installer.
sudo apt-get install ktorrent was all it took to upgrade my installation and fix both the magnet URI and right-click errors. That said, I still haven't managed to load torrents using the magnet links as I simply find that DHT has 'x' tasks queued and nothing happens. But that, I reckon, will be dealt with in another post.
Hope this helps!