[linux-audio-user] JACK configuration: Preventing system lockups

Hi, I'm playing a lot with SuperCollider, which means that I quite often overtax the processor within a JACK app. When I was using a patched 2.4 kernel it used to say it was "zombified" and need to be re-started, but since upgrading to Fedora Core 4 and the Planet CCRMA patched 2.6 kernel it just seems to lock up my system: I might still be able to hear some horribly distorted sound but the mouse pointer doesn't move and keypresses aren't registered for a very long time so I quite often have to do a hard reset (this sometimes used to happen with the 2.4 kernel when plugins in Ardour ran into denormal problems as well). It also seems strange that this can happen quite suddenly after several seconds of QJackCtl saying I'm only using a few percent of the CPU. My question then, is is this a difference in the way JACK is configured? Can I set it up so that it will zombify processes before they lock up the GUI? I tried running Jack in soft mode but I could hardly do anything without getting loads of dropouts. On a related note, is there a JACK configuration HOWTO anywhere? Things I am currently mystified by include the meaning of the phrase "periods per buffer" and how to tell whether my (cheapo laptop internal) soundcard should work better at 44100Hz or 48000. Thanks in advance for any help, Nathaniel Virgo