[PlanetCCRMA] jack and (not jill) lockup

[Aaron]

Hi all,
I start jack and when I try to connect any jack aware app, my system slows to 
a halt, if I don't shut the app down very quickly I run the risk of a system 
lockup.
The worst offender is jack and ardour.

I start jack using qjackctl

here is the startup from qjackctl:
loading driver ..
creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|rt|32bit
control device hw:0
configuring for 48000Hz, period = 1024 frames, buffer = 2 periods
Couldn't open hw:0 for 32bit samples trying 16bit instead
Couldn't open hw:0 for 32bit samples trying 16bit instead
08:31:55.502 Statistics reset.
08:32:00.029 Client activated.
08:32:00.035 Audio connection change.
08:32:00.374 Audio connection graph change.


Is this something jack related or Ardour related. The previous time I ran 
Ardour I got xruns but this time not.


what jack parameters  should I change to get my system up to speed??

Thanks
Aaron