[linux-audio-user] kernel latency question

Every now and then i try to turn my linux box into an audio station. I'm a musician and want to use band in a box. I recently switched from mandrake to debian because i want to have a better understanding/control on my system. I use timidity as i don't own a midi sound card. config (amd athlon 1.4 nv driver snd-ens1371) dual boot->debian sarge(2.6.8 alsa debug+ preemption + voluntary_preemption patch) ->mandrake 10.0 (2.6.3-15-mdk no preemption no patch besides mandrake applied to its stock kernel. what patches? i don't know) 1.Band in a box (with wine) Well my problem is that i cannot get the system (debian) to run band in a box without cratches and glitches whereas it works flawlessly under mandrake! I tried various patches and hints (http://www.affenbande.org/~tapas) i still can't make it work. I even tried to compile mandrake kernel source under debian but raised many other pbs so i gave up.. So ok i stick on mandrake since it works there... But since it does work with mdk i should be able to make it work on debian! Helas not! How comes it works on mandrake and not on debian? Any hint anybody? 2. Jack realtime + realtime module + softsynth Igualito, using jack + qsynth (or even timidity) turns out to be impossible (thousands of xruns, crappy sound, sometimes X crashes ) when i use realtime the system(atically) crashes thousands of xruns mandrake or debian : it is pretty unusable. I tried changing the IRQs from threaded to not threaded, changing the latency with setpci, to no avail. The only thing that improved the xruns a little is: echo 16 > /sys/block/hda/queue/max_sectors_kb If some of you managed to solve theis kind of problem (cheap soundcard, no midi harware) i would like them to share their experience. There is probably something i didn't or i did wrong! Cheers Eric