diff --git a/libs/ardour/ardour/audio_backend.h b/libs/ardour/ardour/audio_backend.h
index 26ced33885..17d7cd4010 100644
--- a/libs/ardour/ardour/audio_backend.h
+++ b/libs/ardour/ardour/audio_backend.h
@@ -282,17 +282,7 @@ class AudioBackend : public PortEngine {
     virtual std::string midi_option () const = 0;
     
     /* State Control */
-
-    /* non-virtual method to avoid possible overrides of default
-     * parameters. See Scott Meyers or other books on C++ to
-     * understand this pattern, or possibly just this:
-     *
-     * http://stackoverflow.com/questions/12139786/good-pratice-default-arguments-for-pure-virtual-method
-     */ 
-    int start (bool for_latency_measurement=false) {
-	    return _start (for_latency_measurement);
-    }
-
+ 
     /** Start using the device named in the most recent call
      * to set_device(), with the parameters set by various
      * the most recent calls to set_sample_rate() etc. etc.
@@ -308,8 +298,24 @@ class AudioBackend : public PortEngine {
      *        any existing systemic latency settings.
      *
      * Return zero if successful, negative values otherwise.
-     */
-    virtual int _start (bool for_latency_measurement) = 0;
+     *
+     *
+     *
+     *
+     * Why is this non-virtual but ::_start() is virtual ?
+     * Virtual methods with default parameters create possible ambiguity
+     * because a derived class may implement the same method with a different
+     * type or value of default parameter.
+     *
+     * So we make this non-virtual method to avoid possible overrides of
+     * default parameters. See Scott Meyers or other books on C++ to understand
+     * this pattern, or possibly just this:
+     *
+     * http://stackoverflow.com/questions/12139786/good-pratice-default-arguments-for-pure-virtual-method
+     */ 
+    int start (bool for_latency_measurement=false) {
+	    return _start (for_latency_measurement);
+    }
 
     /** Stop using the device currently in use. 
      *
@@ -481,6 +487,8 @@ class AudioBackend : public PortEngine {
 
   protected:
     AudioEngine&          engine;
+
+    virtual int _start (bool for_latency_measurement) = 0;
 };
 
 struct AudioBackendInfo {
diff --git a/libs/backends/jack/jack_audiobackend.cc b/libs/backends/jack/jack_audiobackend.cc
index 86e5b9d54c..332b6eec85 100644
--- a/libs/backends/jack/jack_audiobackend.cc
+++ b/libs/backends/jack/jack_audiobackend.cc
@@ -547,8 +547,11 @@ JACKAudioBackend::_start (bool for_latency_measurement)
 	/* Now that we have buffer size and sample rate established, the engine 
 	   can go ahead and do its stuff
 	*/
-	
-	engine.reestablish_ports ();
+
+	if (engine.reestablish_ports ()) {
+		error << _("Could not re-establish ports after connecting to JACK") << endmsg;
+		return -1;
+	}
 
 	if (!jack_port_type_get_buffer_size) {
 		warning << _("This version of JACK is old - you should upgrade to a newer version that supports jack_port_type_get_buffer_size()") << endmsg;
diff --git a/libs/backends/jack/jack_audiobackend.h b/libs/backends/jack/jack_audiobackend.h
index 2c77e6112b..299bb1cefd 100644
--- a/libs/backends/jack/jack_audiobackend.h
+++ b/libs/backends/jack/jack_audiobackend.h
@@ -89,7 +89,6 @@ class JACKAudioBackend : public AudioBackend {
     std::string control_app_name () const;
     void launch_control_app ();
 
-    int _start (bool for_latency_measurement);
     int stop ();
     int freewheel (bool);
 
@@ -272,6 +271,9 @@ class JACKAudioBackend : public AudioBackend {
     */
 
     JACKSession* _session;
+
+  protected:
+    int _start (bool for_latency_measurement);
 };
 
 } // namespace
diff --git a/libs/backends/jack/jack_connection.cc b/libs/backends/jack/jack_connection.cc
index b3d7fcecc4..09e6c9d6e7 100644
--- a/libs/backends/jack/jack_connection.cc
+++ b/libs/backends/jack/jack_connection.cc
@@ -143,7 +143,12 @@ JackConnection::close ()
 	if (_priv_jack) {	
 		int ret = jack_client_close (_priv_jack);
 		_jack = 0;
+
+		/* If we started JACK, it will be closing down */
+		usleep (500000);
+
 		Disconnected (""); /* EMIT SIGNAL */
+
 		return ret;
 	}
 
diff --git a/libs/midi++2/ipmidi_port.cc b/libs/midi++2/ipmidi_port.cc
index 4c0282f1f7..567df99335 100644
--- a/libs/midi++2/ipmidi_port.cc
+++ b/libs/midi++2/ipmidi_port.cc
@@ -44,9 +44,6 @@ typedef int socklen_t;
 inline void closesocket(int s) { ::close(s); }
 #endif
 
-#include <jack/jack.h>
-#include <jack/midiport.h>
-
 #include "pbd/xml++.h"
 #include "pbd/error.h"
 #include "pbd/failed_constructor.h"
diff --git a/libs/midi++2/midi++/mmc.h b/libs/midi++2/midi++/mmc.h
index 01f8bf3b8a..0f2a69d5d7 100644
--- a/libs/midi++2/midi++/mmc.h
+++ b/libs/midi++2/midi++/mmc.h
@@ -20,7 +20,6 @@
 #ifndef __midipp_mmc_h_h__
 #define __midipp_mmc_h_h__
 
-#include <jack/types.h>
 #include "timecode/time.h"
 
 #include "pbd/signals.h"
diff --git a/libs/midi++2/midi++/port.h b/libs/midi++2/midi++/port.h
index a915320fa3..daa2fa2db4 100644
--- a/libs/midi++2/midi++/port.h
+++ b/libs/midi++2/midi++/port.h
@@ -22,7 +22,9 @@
 #include <string>
 #include <iostream>
 
-#include <jack/types.h>
+#include <jack/types.h> /* XXX ... desirable to get rid of this but needed for
+			 * now due to use of JackPortIsXXXX
+			 */
 
 #include <pthread.h>