[LAU] different soundcards for in/out in alsa vs. jack

[Max]

Hi list,

I know that having different soundcards for in and out will lead to 
clock deviations and is generally not a wise thing to do, but my 
question is differently:
Surprisingly it works quite well with ALSA, but not so much with jack.
Both is from Pd. Jack has a plethora of settings, so this could have to 
do with it and make my blanket statement above too simplistic, but I 
wonder is there a general design in jack which makes it harder to rund 
different cards for i/o or do i have the wrong settings? Where to look at?

m.