[LAU] sound card "sync/distortion"

Hi I have a toshiba laptop with a "HDA Intel" sound card and an Edirol USB ua-1a sound card. atte@vestbjerg:~$ lspci | grep -i audio 00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03) Although none of these are pro cards and I don't expect them to be able to perform well with low latency, I have a problem that I feel should be resolveable. If I run jack through qjackctl, clients can often "mess up" jack esp when loading heavy stuff. This results in the sound becoming distorted in a metal-like way. A simple restart of jack seems to resolve this. If I run ChucK with the alsa interface, the problem often is there, seems to be more often the lager the ChucK project (so the more there is to load and the heavier the cpu load is). To me it feels like "something with the soundcard setup", can anyone recognize the problem from my description and what could I do to remedy this? I'm hoping for some magic option to put in /etc/modules* or something like that :-) NB: I'm running ubuntu 8.04 with 2.6.24-21-rt kernel. Realtime performance is setup and otherwise working fine. -- Atte http://atte.dk http://modlys.dk