Check your phpinfo() to see if pdo_sqlite is listed, if not, try adding extension=php_pdo_sqlite.so into the dynamic extensions section of your php.ini
azureus has more features than any other client, and for a lot of people, that's what matters the most.
Azureus has a better UI than KTorrent.
deluge is another good linux torrent clienthttp://www.deluge-torrent.org/
www.qbittorrent.org for Qt/Qt4.2 junkies.
What I meant was that qbittorrent is based on the same libtorrent that deluge is written, but deluge is written in pygtk, and qbittorrent is written using C++ with Qt4.2.
The only thing stopping me using KTorrent is the way it seems to handle uploads. Whenever I had it running, my wife was unable to surf on her laptop (on the wireless network) even though I had the upload speed set to 15 kB/s.
probably a good option for anyone that doesn't know how to configure detailed connection settings
linux bittorrent client that is command line based
http://www.rahul.net/dholmes/ctorrent/
http://en.wikipedia.org/wiki/RTorrent
Too bad that none of the client based torrent programs i have found and used, supports DHT (Besides from the normal Bit-Torrent program in CLI, which turns it on when the normal tracker is dead).