diff --git a/gtk2_ardour/engine_dialog.cc b/gtk2_ardour/engine_dialog.cc
index 9c0a39c554..51cbdda398 100644
--- a/gtk2_ardour/engine_dialog.cc
+++ b/gtk2_ardour/engine_dialog.cc
@@ -215,6 +215,7 @@ EngineControl::EngineControl ()
 	options_packer.attach (realtime_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
 	++row;
 
+	realtime_button.set_active (true);
 	realtime_button.signal_toggled().connect (mem_fun (*this, &EngineControl::realtime_changed));
 	realtime_changed ();
 
diff --git a/gtk2_ardour/processor_box.cc b/gtk2_ardour/processor_box.cc
index b36a97b875..b1baf30bf7 100644
--- a/gtk2_ardour/processor_box.cc
+++ b/gtk2_ardour/processor_box.cc
@@ -176,6 +176,8 @@ ProcessorBox::set_route (boost::shared_ptr<Route> r)
 {
 	connections.clear ();
 
+	/* new route: any existing block on processor redisplay must be meaningless */
+	no_processor_redisplay = false;
 	_route = r;
 
 	connections.push_back (_route->processors_changed.connect (
diff --git a/libs/surfaces/mackie/mackie_control_protocol.cc b/libs/surfaces/mackie/mackie_control_protocol.cc
index 04f44dba5a..7c7fbd9ff5 100644
--- a/libs/surfaces/mackie/mackie_control_protocol.cc
+++ b/libs/surfaces/mackie/mackie_control_protocol.cc
@@ -591,7 +591,7 @@ void MackieControlProtocol::add_port( MIDI::Port & midi_port, int number )
 	cout << "MIDI::Port::ALSA_Sequencer " << MIDI::Port::ALSA_Sequencer << endl;
 	cout << "MIDI::Port::Unknown " << MIDI::Port::Unknown << endl;
 #endif
-	if ( string( midi_port.device() ) == string( "ardour" ) )
+	if ( string( midi_port.device() ) == string( "ardour" ) && midi_port.type() == MIDI::Port::ALSA_Sequencer )
 	{
 		throw MackieControlException( "The Mackie MCU driver will not use a port with device=ardour" );
 	}