[LAD] Failed to connect to session bus for device reservation

Hi Guys, I’m trying to set up a minimal audio system (without X11) based on the ubuntu mini-iso. When trying to start jack, i get this dbus error message: ... sudo /usr/bin/jackd -p512 -dalsa -r48000 -p64 -n2 -D -Chw:MADIFXtest -Phw:MADIFXtest jackdmp 1.9.10 Copyright 2001-2005 Paul Davis and others. Copyright 2004-2013 Grame. jackdmp 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 no message buffer overruns no message buffer overruns no message buffer overruns JACK server starting in realtime mode with priority 10 Failed to connect to session bus for device reservation Unable to autolaunch a dbus-daemon without a $DISPLAY for X11 Audio device hw:MADIFXtest cannot be acquired... Cannot initialize driver JackServer::Open failed with -1 Failed to open server ... I’ve seen others mention the error but have not really found a solution. I guess part of the problem is that I’m not really sure what the error means :-) So if anyone could be so kind to enlighten me? cheers, Fokke