[LAU] QJackCtl and JACK MIDI

Greetings, I want to start working with JACK MIDI, but I'm not sure I understand its requirements. I have a recent QJackCtl with the separate MIDI and ALSA tabs, and I note that in Setup there's a MIDI driver selector. Everything's fine if I leave it at None, but JACK won't start if I select either Raw or Seq. I receive a rather cryptic message " Unknownage with option 'X' " and that's it. JACK is version 0.103, QJackCtl is version 0.3.2, on JAD 1.0. Please advise if other info is needed. Am I missing something obvious ? Also, where can I find the sources to the aseq2jackmidi module ? (Yes, I'm too lazy to search the LAU archives.) Best, dp