[LAU] half a tone upper than the reality [qsynth/jack]

Hello, I'm experiencing some tonality problems with qsynth and jack. I use them on a Debian SID, with non-realtime kernel. I use both rosegarden and nted, and both package give me the same results. The problem is very simple : all the "melodic" instrument are played half a tone upper than they should (a A sound like a A#). I thought the problem was coming from my non-realtime kernel, but a friend of mine has the same problem on an Ubuntu Studio distribution with a realtime kernel and realtime enabled in jack. The problem doesn't come from the soundfonts we use (there are many, Crisi General 1.8, Super Evandro Drummer, and others...), as another friend of mine, running also with Ubuntu Studio and the same settings than the previous one (buffers sizes, etc.) doesn't have the problem. I don't know what from it could come. Any idea? Thanks a lot. -- ============================== ORL /// AMMD Booking (www.ammd.net) ° Sebkha-Chott (www.sebkhachott.net - Ohreland [FR]) - next touring period: 04-06/2008 ° Unexpect (www.unexpect.com - Montréal [CA]) - Europe tour w/ Sebkha-Chott period: 09-12/2008 ° La Muette (www.myspace.com/muette - Paris [FR]) - next touring period: 05/2008 (Bretagne) ° Mel-P (www.mel-p.net - Le Mans [FR]) - next touring period: 09/2008 Phone: +33 (0)95 234 72 48