dbus-send --system /org/rncbc/qjackctl org.rncbc.qjackctl.start
dbus-send --system /org/rncbc/qjackctl org.rncbc.qjackctl.stop
is equivalent to pressing qjackctl's start&stop buttons.
hmm, this would be what I want, but it didn't work here (jaunty). any
permissions missing?