ROXTerm uses the "session" bus, which should be started along with your
desktop environment. Current versions of ROX, GNOME, XFCE, and KDE session
managers all launch D-BUS. If you use some other session/desktop/window
manager which doesn't launch D-BUS you can start it by inserting something
like this near the start of your .xinitrc or .xsession:

  if test -z "$DBUS_SESSION_BUS_ADDRESS" ; then
    eval `dbus-launch --sh-syntax --exit-with-session`
    export DBUS_SESSION_BUS_ADDRESS
  fi
