width_control->Changed.connect (panvalue_connections, invalidator(*this), boost::bind (&StereoPanner::value_change, this), gui_context());
_panner_shell->Changed.connect (panshell_connections, invalidator (*this), boost::bind (&StereoPanner::bypass_handler, this), gui_context());
+ _panner_shell->PannableChanged.connect (panshell_connections, invalidator (*this), boost::bind (&StereoPanner::pannable_handler, this), gui_context());
ColorsChanged.connect (sigc::mem_fun (*this, &StereoPanner::color_handler));