[root@Acer mickey]# jackd -d alsa
jackd 0.118.0
Copyright 2001-2009 Paul Davis, Stephane Letz, Jack O'Quinn, Torben
Hohn and others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
JACK compiled with System V SHM support.
loading driver ..
creating alsa driver ...
hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit
control device hw:0
the playback device "hw:0" is already in use. Please stop the
application using it and run JACK again
cannot load driver module alsa
There are no other applications using the sound system.
Have you tried starting jackd just after login? Even if an application is not making any audible sounds it can still using the sound card. firefox does this.
Also I think you need to edit your /etc/asound.conf file to set up jack properly. I haven't been able to get this to work properly either. I can get jark started and running ok, but then I can't get it to make a sound.
Sam