diff --git a/SConstruct b/SConstruct
index 79ac56b6f0..95fa911a8d 100644
--- a/SConstruct
+++ b/SConstruct
@@ -44,6 +44,7 @@ opts.AddOptions(
     BoolOption('UNIVERSAL', 'Compile as universal binary.  Requires that external libraries are already universal.', 0),
     BoolOption('VERSIONED', 'Add revision information to ardour/gtk executable name inside the build directory', 0),
     BoolOption('VST', 'Compile with support for VST', 0),
+    BoolOption('GPROFILE', 'Compile with support for gprofile (Developers only)', 0),
     BoolOption('TRANZPORT', 'Compile with support for Frontier Designs (if libusb is available)', 1)
 )
 
@@ -531,7 +532,10 @@ env = conf.Finish()
 #
 
 opt_flags = []
-debug_flags = [ '-g' ]
+if env['GPROFILE'] == 1:
+    debug_flags = [ '-g', '-pg' ]
+else:
+    debug_flags = [ '-g' ]
 
 # guess at the platform, used to define compiler flags
 
diff --git a/gtk2_ardour/ardour_ui_dialogs.cc b/gtk2_ardour/ardour_ui_dialogs.cc
index a0d772dbf1..063810dd83 100644
--- a/gtk2_ardour/ardour_ui_dialogs.cc
+++ b/gtk2_ardour/ardour_ui_dialogs.cc
@@ -153,7 +153,7 @@ ARDOUR_UI::connect_to_session (Session *s)
 
 	second_connection = Glib::signal_timeout().connect (mem_fun(*this, &ARDOUR_UI::every_second), 1000);
 	point_one_second_connection = Glib::signal_timeout().connect (mem_fun(*this, &ARDOUR_UI::every_point_one_seconds), 100);
-	// point_oh_five_second_connection = Glib::signal_timeout().connect (mem_fun(*this, &ARDOUR_UI::every_point_oh_five_seconds), 50);
+	point_oh_five_second_connection = Glib::signal_timeout().connect (mem_fun(*this, &ARDOUR_UI::every_point_oh_five_seconds), 50);
 	point_zero_one_second_connection = Glib::signal_timeout().connect (mem_fun(*this, &ARDOUR_UI::every_point_zero_one_seconds), 40);
 }
 
diff --git a/gtk2_ardour/audio_streamview.cc b/gtk2_ardour/audio_streamview.cc
index aa54af86fb..5a27d6b2a9 100644
--- a/gtk2_ardour/audio_streamview.cc
+++ b/gtk2_ardour/audio_streamview.cc
@@ -526,7 +526,7 @@ AudioStreamView::setup_rec_box ()
 			rec_rects.push_back (recbox);
 			
 			screen_update_connection.disconnect();
-			screen_update_connection = ARDOUR_UI::instance()->SuperRapidScreenUpdate.connect (mem_fun (*this, &AudioStreamView::update_rec_box));	
+			screen_update_connection = ARDOUR_UI::instance()->MidRapidScreenUpdate.connect (mem_fun (*this, &AudioStreamView::update_rec_box));	
 			rec_updating = true;
 			rec_active = true;
 
diff --git a/gtk2_ardour/canvas-simplerect.c b/gtk2_ardour/canvas-simplerect.c
index d59096e68b..288289183f 100644
--- a/gtk2_ardour/canvas-simplerect.c
+++ b/gtk2_ardour/canvas-simplerect.c
@@ -264,11 +264,17 @@ gnome_canvas_simplerect_reset_bounds (GnomeCanvasItem *item)
 	double x1, x2, y1, y2;
 	double old_x1, old_x2, old_y1, old_y2;
 	double a, b, c, d;
-	
-	old_x1 = item->x1;
-	old_y1 = item->y1;
-	old_x2 = item->x2;
-	old_y2 = item->y2;
+	ArtIRect intersection, old, new;
+
+	old.x0 = old_x1 = item->x1;
+	old.y0 = old_y1 = item->y1;
+	old.x1 = old_x2 = item->x2;
+	old.y1 = old_y2 = item->y2;
+
+	new.x0 = x1;
+	new.y0 = y1;
+	new.x1 = x2;
+	new.y1 = y2;
 
 	gnome_canvas_simplerect_bounds (item, &x1, &y1, &x2, &y2);
 	gnome_canvas_item_i2w (item, &x1, &y1);
@@ -288,6 +294,8 @@ gnome_canvas_simplerect_reset_bounds (GnomeCanvasItem *item)
 
 	/* now queue redraws for changed areas */
 		
+	art_irect_intersect (&intersection, &old, &new);
+#if 0
 		a = MIN(item->x1, old_x1); 
 		b = MAX(item->x1, old_x1);
 
@@ -304,7 +312,15 @@ gnome_canvas_simplerect_reset_bounds (GnomeCanvasItem *item)
 		d = MAX(d,item->y2);
 		d = MAX(d, old_y2);
 
+		fprintf (stderr, "%p REDRAW %g,%g %g,%g\n", simplerect, a, c, b + 0.5, d + 0.5);
 		gnome_canvas_request_redraw (item->canvas, a, c, b + 0.5, d + 0.5);
+#else 
+		gnome_canvas_request_redraw (item->canvas, 
+					     intersection.x0,
+					     intersection.y0,
+					     intersection.x1,
+					     intersection.y1);
+#endif
 }
 
 /* 
@@ -509,7 +525,7 @@ gnome_canvas_simplerect_render (GnomeCanvasItem *item,
 	if (parent_class->render) {
 		(*parent_class->render) (item, buf);
 	}
-
+	
 	if (buf->is_bg) {
 
 #ifdef HARLEQUIN_DEBUGGING