[LAU] Confusing qjackctl playback devices, no jackd output

Hi, recently something weird happened. As usual in this cases, I'm not aware of making any changes, this happened all without my intervention. This reinforces my theory of a leprechaun infestation at home, but I'll leave that for another mailing list. The symptoms: I launch qjackctl, start jackd, and then hydrogen. When I hit "play", there is no sound. There are no errors in qjackctl's message window, and hydrogen is playing nicely (vu meters are going up and down as if nothing happened). After messing around for a while, I found that I could make hydrogen sound again changing the connections in qjackctl "Connections" window: instead of connecting the two outputs of hydrogen to "playback_1" and "playback_2" (which is the default as soon as hydrogen is started), I connected them to "playback_7" and "playback_8". I have a built-in HDA-intel sound card, and I believe that these outputs are "side-left" and "side-right". But I had never had to do this, playback_1 and playback_2 always worked. I'm using headphones, in case that's important. More interesting yet: while hydrogen worked flawlessly with playback_7 and playback_8, I tried to do the same with rosegarden and it didn't work. I haven't tested other jack-enabled tools yet, but I'll do it ASAP to see if hydrogen is the exception or the norm. Is it possible that due to some leprechaun-induced change in the system (or maybe, though not as probable, some change that I did and can't remember now) the playback devices in qjackctl have changed? How could I define them so playback_1 and playback_2 went back to their "proper" meanings? I'm aware that this is not really a well defined problem report, but I'll gladly welcome any suggestion or tip that could help with this. And with the leprechauns. Pesky little beasts. Thanks in advance, -- Roberto Suarez Soto Ave Nevis, ave ferrum, Ave tela, ave cruor, Ave pugna, ave moritur.