diff --git a/gtk2_ardour/ardour_ui2.cc b/gtk2_ardour/ardour_ui2.cc
index 9a964fe519..ed7c4951e1 100644
--- a/gtk2_ardour/ardour_ui2.cc
+++ b/gtk2_ardour/ardour_ui2.cc
@@ -451,23 +451,6 @@ ARDOUR_UI::setup_transport ()
 	transport_tearoff_hbox.pack_start (alert_box, false, false);
 }
 
-void
-ARDOUR_UI::setup_clock ()
-{
-	ARDOUR_UI::Clock.connect (bind (mem_fun (big_clock, &AudioClock::set), false));
-	
-	big_clock_window = new Window (WINDOW_TOPLEVEL);
-	
-	big_clock_window->set_border_width (0);
-	big_clock_window->add  (big_clock);
-	big_clock_window->set_title (_("ardour: clock"));
-	big_clock_window->set_type_hint (Gdk::WINDOW_TYPE_HINT_MENU);
-	big_clock_window->signal_realize().connect (bind (sigc::ptr_fun (set_decoration), big_clock_window,  (Gdk::DECOR_BORDER|Gdk::DECOR_RESIZEH)));
-	big_clock_window->signal_unmap().connect (bind (sigc::ptr_fun(&ActionManager::uncheck_toggleaction), X_("<Actions>/Common/ToggleBigClock")));
-
-	manage_window (*big_clock_window);
-}
-
 void
 ARDOUR_UI::manage_window (Window& win)
 {
diff --git a/gtk2_ardour/ardour_ui_ed.cc b/gtk2_ardour/ardour_ui_ed.cc
index eebe33bf58..d7c294c681 100644
--- a/gtk2_ardour/ardour_ui_ed.cc
+++ b/gtk2_ardour/ardour_ui_ed.cc
@@ -26,6 +26,8 @@
 
 #include <pbd/pathscanner.h>
 
+#include <gtkmm2ext/utils.h>
+
 #include "ardour_ui.h"
 #include "public_editor.h"
 #include "audio_clock.h"
@@ -39,10 +41,12 @@
 
 #include "i18n.h"
 
+using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
-using namespace Gtk;
 using namespace Gtkmm2ext;
+using namespace Gtk;
+using namespace Glib;
 using namespace sigc;
 
 int
@@ -558,3 +562,24 @@ ARDOUR_UI::build_menu_bar ()
 	menu_bar_base.set_name ("MainMenuBar");
 	menu_bar_base.add (menu_hbox);
 }
+
+void
+ARDOUR_UI::setup_clock ()
+{
+	ARDOUR_UI::Clock.connect (bind (mem_fun (big_clock, &AudioClock::set), false));
+	
+	big_clock_window = new Window (WINDOW_TOPLEVEL);
+	
+	big_clock_window->set_border_width (0);
+	big_clock_window->add  (big_clock);
+	big_clock_window->set_title (_("ardour: clock"));
+	big_clock_window->set_type_hint (Gdk::WINDOW_TYPE_HINT_MENU);
+	big_clock_window->signal_realize().connect (bind (sigc::ptr_fun (set_decoration), big_clock_window,  (Gdk::DECOR_BORDER|Gdk::DECOR_RESIZEH)));
+	big_clock_window->signal_unmap().connect (bind (sigc::ptr_fun(&ActionManager::uncheck_toggleaction), X_("<Actions>/Common/ToggleBigClock")));
+
+	if (editor) {
+		editor->ensure_float (*big_clock_window);
+	}
+
+	manage_window (*big_clock_window);
+}
diff --git a/gtk2_ardour/automation_line.h b/gtk2_ardour/automation_line.h
index 52193ecc4c..eb2d204513 100644
--- a/gtk2_ardour/automation_line.h
+++ b/gtk2_ardour/automation_line.h
@@ -96,7 +96,7 @@ class ControlPoint
 	ShapeType _shape;
 };
 
-class AutomationLine : public sigc::trackable, public PBD::StatefulDestructible
+class AutomationLine : public PBD::StatefulDestructible
 {
   public:
         AutomationLine (const string & name, TimeAxisView&, ArdourCanvas::Group&, ARDOUR::AutomationList&);
diff --git a/libs/ardour/ardour/diskstream.h b/libs/ardour/ardour/diskstream.h
index cffe02e859..0afed75348 100644
--- a/libs/ardour/ardour/diskstream.h
+++ b/libs/ardour/ardour/diskstream.h
@@ -54,7 +54,7 @@ class Session;
 class Playlist;
 class IO;
 
- class Diskstream : public sigc::trackable, public PBD::StatefulDestructible
+ class Diskstream : public PBD::StatefulDestructible
 {	
   public:
 	enum Flag {
diff --git a/libs/ardour/ardour/location.h b/libs/ardour/ardour/location.h
index 2dd49847fb..1f1c02d67c 100644
--- a/libs/ardour/ardour/location.h
+++ b/libs/ardour/ardour/location.h
@@ -42,7 +42,7 @@ using std::string;
 
 namespace ARDOUR {
 
-class Location : public sigc::trackable, public PBD::StatefulDestructible
+class Location : public PBD::StatefulDestructible
 {
   public:
 	enum Flags {
diff --git a/libs/ardour/ardour/plugin.h b/libs/ardour/ardour/plugin.h
index bc71da84ae..e0b2dfc12b 100644
--- a/libs/ardour/ardour/plugin.h
+++ b/libs/ardour/ardour/plugin.h
@@ -77,7 +77,7 @@ class PluginInfo {
 typedef boost::shared_ptr<PluginInfo> PluginInfoPtr;
 typedef std::list<PluginInfoPtr> PluginInfoList;
 
-class Plugin : public PBD::StatefulDestructible, public sigc::trackable
+class Plugin : public PBD::StatefulDestructible
 {
   public:
 	Plugin (ARDOUR::AudioEngine&, ARDOUR::Session&);
diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index ca7c38b281..2453f30cbf 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -103,7 +103,7 @@ using std::string;
 using std::map;
 using std::set;
 
-class Session : public sigc::trackable, public PBD::StatefulDestructible
+class Session : public PBD::StatefulDestructible
 
 {
   private:
@@ -1434,10 +1434,9 @@ class Session : public sigc::trackable, public PBD::StatefulDestructible
 	typedef map<PBD::ID,boost::shared_ptr<AudioRegion> > AudioRegionList;
 	AudioRegionList audio_regions;
 	
-	void region_renamed (boost::shared_ptr<Region>);
-	void region_changed (Change, boost::shared_ptr<Region>);
 	void add_region (boost::shared_ptr<Region>);
-	void remove_region (boost::shared_ptr<Region>);
+	void region_changed (Change, boost::weak_ptr<Region>);
+	void remove_region (boost::weak_ptr<Region>);
 
 	int load_regions (const XMLNode& node);
 
diff --git a/libs/ardour/ardour/source.h b/libs/ardour/ardour/source.h
index 40594f744b..7e05e628ac 100644
--- a/libs/ardour/ardour/source.h
+++ b/libs/ardour/ardour/source.h
@@ -33,7 +33,7 @@ namespace ARDOUR {
 
 class Session;
 
-class Source : public PBD::StatefulDestructible, public sigc::trackable
+class Source : public PBD::StatefulDestructible
 {
   public:
 	Source (Session&, std::string name);
diff --git a/libs/ardour/ardour/state_manager.h b/libs/ardour/ardour/state_manager.h
index 99bfcfc3ce..e123b2cb37 100644
--- a/libs/ardour/ardour/state_manager.h
+++ b/libs/ardour/ardour/state_manager.h
@@ -13,7 +13,7 @@ namespace ARDOUR {
 
 typedef uint32_t state_id_t;
 
-class StateManager : public sigc::trackable
+class StateManager : public virtual sigc::trackable
 {
   public:
 	struct State {
diff --git a/libs/ardour/audioregion.cc b/libs/ardour/audioregion.cc
index e403130882..1a09cad032 100644
--- a/libs/ardour/audioregion.cc
+++ b/libs/ardour/audioregion.cc
@@ -31,6 +31,7 @@
 
 #include <pbd/basename.h>
 #include <pbd/xml++.h>
+#include <pbd/stacktrace.h>
 
 #include <ardour/audioregion.h>
 #include <ardour/session.h>
@@ -325,6 +326,7 @@ AudioRegion::AudioRegion (SourceList& srcs, const XMLNode& node)
 
 AudioRegion::~AudioRegion ()
 {
+	notify_callbacks ();
 	GoingAway (); /* EMIT SIGNAL */
 }
 
diff --git a/libs/ardour/region.cc b/libs/ardour/region.cc
index 528bb52a01..ccdf3bdb5d 100644
--- a/libs/ardour/region.cc
+++ b/libs/ardour/region.cc
@@ -147,9 +147,7 @@ Region::Region (const XMLNode& node)
 
 Region::~Region ()
 {
-	notify_callbacks ();
-
-	/* derived classes must emit GoingAway */
+	/* derived classes must call notify_callbacks() and then emit GoingAway */
 }
 
 void
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index da147fc2d4..d5ff3d223c 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -463,8 +463,15 @@ Session::~Session ()
 	cerr << "delete audio regions\n";
 #endif /* TRACK_DESTRUCTION */
 	
-	for (AudioRegionList::iterator i = audio_regions.begin(); i != audio_regions.end(); ++i) {
+	for (AudioRegionList::iterator i = audio_regions.begin(); i != audio_regions.end(); ) {
+		AudioRegionList::iterator tmp;
+
+		tmp = i;
+		++tmp;
+
 		i->second->drop_references ();
+
+		i = tmp;
 	}
 
 	audio_regions.clear ();
@@ -2447,15 +2454,21 @@ Session::add_region (boost::shared_ptr<Region> region)
 	set_dirty();
 	
 	if (added) {
-		region->GoingAway.connect (sigc::bind (mem_fun (*this, &Session::remove_region), region));
-		region->StateChanged.connect (sigc::bind (mem_fun (*this, &Session::region_changed), region));
+		region->GoingAway.connect (sigc::bind (mem_fun (*this, &Session::remove_region), boost::weak_ptr<Region>(region)));
+		region->StateChanged.connect (sigc::bind (mem_fun (*this, &Session::region_changed), boost::weak_ptr<Region>(region)));
 		AudioRegionAdded (ar); /* EMIT SIGNAL */
 	}
 }
 
 void
-Session::region_changed (Change what_changed, boost::shared_ptr<Region> region)
+Session::region_changed (Change what_changed, boost::weak_ptr<Region> weak_region)
 {
+	boost::shared_ptr<Region> region (weak_region.lock ());
+
+	if (!region) {
+		return;
+	}
+
 	if (what_changed & Region::HiddenChanged) {
 		/* relay hidden changes */
 		RegionHiddenChange (region);
@@ -2463,15 +2476,15 @@ Session::region_changed (Change what_changed, boost::shared_ptr<Region> region)
 }
 
 void
-Session::region_renamed (boost::shared_ptr<Region> region)
-{
-	add_region (region);
-}
-
-void
-Session::remove_region (boost::shared_ptr<Region> region)
+Session::remove_region (boost::weak_ptr<Region> weak_region)
 {
 	AudioRegionList::iterator i;
+	boost::shared_ptr<Region> region (weak_region.lock ());
+
+	if (!region) {
+		return;
+	}
+
 	boost::shared_ptr<AudioRegion> ar;
 	bool removed = false;
 
@@ -2482,7 +2495,6 @@ Session::remove_region (boost::shared_ptr<Region> region)
 			if ((i = audio_regions.find (region->id())) != audio_regions.end()) {
 				audio_regions.erase (i);
 				removed = true;
-				cerr << "done\n";
 			}
 
 		} else {
diff --git a/libs/gtkmm2ext/gtk_ui.cc b/libs/gtkmm2ext/gtk_ui.cc
index 55a6bebb02..a2a3404041 100644
--- a/libs/gtkmm2ext/gtk_ui.cc
+++ b/libs/gtkmm2ext/gtk_ui.cc
@@ -253,7 +253,8 @@ static bool idle_quit ()
 void
 UI::do_quit ()
 {
-	Glib::signal_idle().connect (sigc::ptr_fun (idle_quit));
+	Gtk::Main::quit ();
+	// Glib::signal_idle().connect (sigc::ptr_fun (idle_quit));
 }
 
 void
diff --git a/libs/pbd/pbd/destructible.h b/libs/pbd/pbd/destructible.h
index 126bd04bba..6692ff564c 100644
--- a/libs/pbd/pbd/destructible.h
+++ b/libs/pbd/pbd/destructible.h
@@ -5,7 +5,7 @@
 
 namespace PBD {
 
-class Destructible {
+class Destructible : public virtual sigc::trackable {
   public:
 	Destructible() {}
 	virtual ~Destructible () {}