diff --git a/gtk2_ardour/editor.h b/gtk2_ardour/editor.h
index a508e1d080..558f24f31c 100644
--- a/gtk2_ardour/editor.h
+++ b/gtk2_ardour/editor.h
@@ -1016,8 +1016,6 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	bool deferred_control_scroll (framepos_t);
 	sigc::connection control_scroll_connection;
 
-	gdouble get_trackview_group_vertical_offset () const { return vertical_adjustment.get_value (); }
-
 	ArdourCanvas::Group* get_background_group () const { return _background_group; }
 	ArdourCanvas::Group* get_trackview_group () const { return _trackview_group; }
 	void tie_vertical_scrolling ();
diff --git a/gtk2_ardour/editor_canvas.cc b/gtk2_ardour/editor_canvas.cc
index 3f0098dcd0..faaae52ff6 100644
--- a/gtk2_ardour/editor_canvas.cc
+++ b/gtk2_ardour/editor_canvas.cc
@@ -33,6 +33,7 @@
 #include "canvas/rectangle.h"
 #include "canvas/pixbuf.h"
 #include "canvas/text.h"
+#include "canvas/debug.h"
 
 #include "ardour_ui.h"
 #include "editor.h"
@@ -101,10 +102,14 @@ Editor::initialize_canvas ()
 
 
 	_background_group = new ArdourCanvas::Group (_track_canvas->root());
+	CANVAS_DEBUG_NAME (_background_group, "Canvas Background");
 	_master_group = new ArdourCanvas::Group (_track_canvas->root());
+	CANVAS_DEBUG_NAME (_master_group, "Canvas Master");
 
 	_trackview_group = new ArdourCanvas::Group (_master_group);
+	CANVAS_DEBUG_NAME (_trackview_group, "Canvas TrackViews");
 	_region_motion_group = new ArdourCanvas::Group (_trackview_group);
+	CANVAS_DEBUG_NAME (_region_motion_group, "Canvas Region Motion");
 
 	meter_bar_group = new ArdourCanvas::Group (_time_bars_canvas->root ());
 	meter_bar = new ArdourCanvas::Rectangle (meter_bar_group, ArdourCanvas::Rect (0.0, 0.0, ArdourCanvas::COORD_MAX, timebar_height - 1));
@@ -487,7 +492,7 @@ Editor::maybe_autoscroll (bool allow_horiz, bool allow_vert, bool moving_left, b
 	/* Note whether we're fudging the autoscroll (see autoscroll_fudge_threshold) */
 	_autoscroll_fudging = (distance < autoscroll_fudge_threshold ());
 
-	double const ty = _drags->current_pointer_y() - get_trackview_group_vertical_offset ();
+	double const ty = _drags->current_pointer_y();
 
 	autoscroll_y = 0;
 	autoscroll_x = 0;
@@ -558,7 +563,7 @@ Editor::autoscroll_canvas ()
 
 	if (autoscroll_y_distance != 0) {
 		if (autoscroll_y > 0) {
-			autoscroll_y_distance = (_drags->current_pointer_y() - (get_trackview_group_vertical_offset() + _visible_canvas_height)) / 3;
+			autoscroll_y_distance = (_drags->current_pointer_y() - _visible_canvas_height) / 3;
 		} else if (autoscroll_y < 0) {
 
 			autoscroll_y_distance = (vertical_adjustment.get_value () - _drags->current_pointer_y()) / 3;
@@ -754,23 +759,6 @@ Editor::set_horizontal_position (double p)
 	HorizontalPositionChanged (); /* EMIT SIGNAL */
 }
 
-// CAIROCANVAS
-#if 0
-void
-Editor::scroll_canvas_vertically ()
-{
-	/* vertical scrolling only */
-
-	double y_delta;
-
-	y_delta = last_trackview_group_vertical_offset - get_trackview_group_vertical_offset ();
-	_trackview_group->move (0, y_delta);
-	_background_group->move (0, y_delta);
-
-	last_trackview_group_vertical_offset = get_trackview_group_vertical_offset ();
-}
-#endif
-
 void
 Editor::color_handler()
 {
diff --git a/gtk2_ardour/editor_drag.cc b/gtk2_ardour/editor_drag.cc
index d753d59551..1b9a820ae6 100644
--- a/gtk2_ardour/editor_drag.cc
+++ b/gtk2_ardour/editor_drag.cc
@@ -670,12 +670,16 @@ RegionMotionDrag::motion (GdkEvent* event, bool first_move)
 			/* Reparent to a non scrolling group so that we can keep the
 			   region selection above all time axis views.
 			   Reparenting means that we will have to move the region view
-			   later, as the two parent groups have different coordinates.
+			   within its new parent, as the two parent groups have different coordinates.
 			*/
 
+			ArdourCanvas::Group* rvg = rv->get_canvas_group();
+			Duple rv_canvas_offset = rvg->item_to_canvas (Duple (0,0));
+
 			rv->get_canvas_group()->reparent (_editor->_region_motion_group);
-			
+
 			rv->fake_set_opaque (true);
+			rvg->set_position (rv_canvas_offset);
 		}
 
 		/* If we have moved tracks, we'll fudge the layer delta so that the
@@ -725,8 +729,7 @@ RegionMotionDrag::motion (GdkEvent* event, bool first_move)
 
 			/* Get the y coordinate of the top of the track that this region is now on */
 			tv->canvas_display()->item_to_canvas (x, y);
-			y += _editor->get_trackview_group_vertical_offset();
-			
+
 			/* And adjust for the layer that it should be on */
 			StreamView* cv = tv->view ();
 			switch (cv->layer_display ()) {
diff --git a/gtk2_ardour/editor_tempodisplay.cc b/gtk2_ardour/editor_tempodisplay.cc
index 30aab87d05..b717ef5464 100644
--- a/gtk2_ardour/editor_tempodisplay.cc
+++ b/gtk2_ardour/editor_tempodisplay.cc
@@ -193,9 +193,8 @@ Editor::draw_measures (ARDOUR::TempoMap::BBTPointList::const_iterator& begin,
 	if (tempo_lines == 0) {
 		tempo_lines = new TempoLines (*_track_canvas_viewport, time_line_group, physical_screen_height(get_window()));
 	}
-
-	// CAIROCANVAS
-	// tempo_lines->draw (begin, end, frames_per_unit);
+	
+	tempo_lines->draw (begin, end, samples_per_pixel);
 }
 
 void
diff --git a/gtk2_ardour/public_editor.h b/gtk2_ardour/public_editor.h
index 9fbf4533b4..42ff531a35 100644
--- a/gtk2_ardour/public_editor.h
+++ b/gtk2_ardour/public_editor.h
@@ -380,7 +380,6 @@ class PublicEditor : public Gtk::Window, public PBD::StatefulDestructible {
 	virtual Gtk::HBox& get_status_bar_packer() = 0;
 #endif
 
-	virtual gdouble get_trackview_group_vertical_offset () const = 0;
 	virtual ArdourCanvas::Group* get_trackview_group () const = 0;
 	virtual ArdourCanvas::Group* get_background_group () const = 0;
 
diff --git a/gtk2_ardour/tempo_lines.cc b/gtk2_ardour/tempo_lines.cc
index 5cb059cbee..cd923d88a9 100644
--- a/gtk2_ardour/tempo_lines.cc
+++ b/gtk2_ardour/tempo_lines.cc
@@ -123,11 +123,11 @@ TempoLines::draw (const ARDOUR::TempoMap::BBTPointList::const_iterator& begin,
 	// Tempo map hasn't changed and we're entirely within a clean
 	// range, don't need to do anything.  Yay.
 	if (needed_left >= _clean_left && needed_right <= _clean_right) {
-		// cout << endl << "*** LINE CACHE PERFECT HIT" << endl;
+		// cerr << endl << "*** LINE CACHE PERFECT HIT" << endl;
 		return;
 	}
 
-	//cout << endl << "*** LINE CACHE MISS" << endl;
+	// cerr << endl << "*** LINE CACHE MISS" << endl;
 
 	bool invalidated = false;
 
@@ -169,7 +169,7 @@ TempoLines::draw (const ARDOUR::TempoMap::BBTPointList::const_iterator& begin,
 			
 			// Steal from the right
 			if (left->first > needed_left && li != steal && steal->first > needed_right) {
-				//cout << "*** STEALING FROM RIGHT" << endl;
+				// cerr << "*** STEALING FROM RIGHT" << endl;
 				double const x = steal->first;
 				line = steal->second;
 				_lines.erase(steal);
@@ -208,7 +208,7 @@ TempoLines::draw (const ARDOUR::TempoMap::BBTPointList::const_iterator& begin,
 			
 			// Create a new line
 		} else if (_lines.size() < needed || _lines.size() < MAX_CACHED_LINES) {
-			//cout << "*** CREATING LINE" << endl;
+			// cerr << "*** CREATING LINE" << endl;
 			/* if we already have a line there ... don't sweat it */
 			if (_lines.find (xpos) == _lines.end()) {
 				line = new ArdourCanvas::Line (_group);
@@ -222,7 +222,7 @@ TempoLines::draw (const ARDOUR::TempoMap::BBTPointList::const_iterator& begin,
 			
 			// Steal from the left
 		} else {
-			//cout << "*** STEALING FROM LEFT" << endl;
+			// cerr << "*** STEALING FROM LEFT" << endl;
 			if (_lines.find (xpos) == _lines.end()) {
 				Lines::iterator steal = _lines.begin();
 				double const x = steal->first;
diff --git a/gtk2_ardour/time_axis_view.cc b/gtk2_ardour/time_axis_view.cc
index 433eee350d..a426656cf6 100644
--- a/gtk2_ardour/time_axis_view.cc
+++ b/gtk2_ardour/time_axis_view.cc
@@ -373,7 +373,7 @@ TimeAxisView::controls_ebox_motion (GdkEventMotion* ev)
 		*/
 		int tx, ty;
 		controls_ebox.translate_coordinates (*control_parent, ev->x, ev->y, tx, ty);
-		ev->y = ty - _editor.get_trackview_group_vertical_offset();
+		ev->y = ty;
 		_editor.drags()->motion_handler ((GdkEvent *) ev, false);
 		_editor.maybe_autoscroll (false, true, false, ev->y_root < _resize_drag_start);
 
diff --git a/libs/canvas/canvas.cc b/libs/canvas/canvas.cc
index b849894bf0..da34a73c21 100644
--- a/libs/canvas/canvas.cc
+++ b/libs/canvas/canvas.cc
@@ -100,18 +100,6 @@ Canvas::render (Rect const & area, Cairo::RefPtr<Cairo::Context> const & context
 	// checkpoint ("render", "-> render");
 	render_count = 0;
 	
-#ifdef CANVAS_DEBUG
-	if (getenv ("ARDOUR_HARLEQUIN_CANVAS")) {
-		/* light up the canvas to show redraws */
-		context->set_source_rgba (random()%255 / 255.0,
-					  random()%255 / 255.0,
-					  random()%255 / 255.0,
-					  255);
-		context->rectangle (area.x0, area.y0, area.width(), area.height());
-		context->fill ();
-	}
-#endif
-
 	context->save ();
 
 	/* clip to the requested area */
@@ -143,6 +131,17 @@ Canvas::render (Rect const & area, Cairo::RefPtr<Cairo::Context> const & context
 
 	context->restore ();
 
+#ifdef CANVAS_DEBUG
+	if (getenv ("ARDOUR_HARLEQUIN_CANVAS")) {
+		/* light up the canvas to show redraws */
+		context->set_source_rgba (random()%255 / 255.0,
+					  random()%255 / 255.0,
+					  random()%255 / 255.0,
+					  255);
+		context->rectangle (area.x0, area.y0, area.width(), area.height());
+		context->fill ();
+	}
+#endif
 	// checkpoint ("render", "<- render");
 }
 
@@ -225,10 +224,15 @@ void
 Canvas::item_moved (Item* item, boost::optional<Rect> pre_change_parent_bounding_box)
 {
 	if (pre_change_parent_bounding_box) {
-		/* request a redraw of where the item used to be; we have to use the
-		   parent's coordinates here as item bounding boxes do not change
-		   when the item moves.
-		*/
+		/* request a redraw of where the item used to be. The box has
+		 * to be in parent coordinate space since the bounding box of
+		 * an item does not change when moved. If we use
+		 * item->item_to_canvas() on the old bounding box, we will be
+		 * using the item's new position, and so will compute the wrong
+		 * invalidation area. If we use the parent (which has not
+		 * moved, then this will work.
+		 */
+
 		queue_draw_item_area (item->parent(), pre_change_parent_bounding_box.get ());
 	}
 
@@ -246,7 +250,9 @@ Canvas::item_moved (Item* item, boost::optional<Rect> pre_change_parent_bounding
 void
 Canvas::queue_draw_item_area (Item* item, Rect area)
 {
-	request_redraw (item->item_to_canvas (area));
+	ArdourCanvas::Rect canvas_area = item->item_to_canvas (area);
+	// cerr << "CANVAS Invalidate " << area << " TRANSLATE AS " << canvas_area << endl;
+	request_redraw (canvas_area);
 }
 
 /** @return An XML description of the canvas and its objects */
@@ -554,6 +560,7 @@ void
 GtkCanvas::request_redraw (Rect const & request)
 {
 	Rect area = canvas_to_window (request);
+	// cerr << "Invalidate " << request << " TRANSLATE AS " << area << endl;
 	queue_draw_area (floor (area.x0), floor (area.y0), ceil (area.x1) - floor (area.x0), ceil (area.y1) - floor (area.y0));
 }
 
diff --git a/libs/canvas/canvas/item.h b/libs/canvas/canvas/item.h
index fc66754ed4..7f1321b260 100644
--- a/libs/canvas/canvas/item.h
+++ b/libs/canvas/canvas/item.h
@@ -108,9 +108,12 @@ public:
 	/* XXX: it's a pity these aren't the same form as item_to_parent etc.,
 	   but it makes a bit of a mess in the rest of the code if they are not.
 	*/
-	void canvas_to_item (Coord &, Coord &) const;
+
+        void canvas_to_item (Coord &, Coord &) const;
+        Duple canvas_to_item (Duple const &) const;
 	void item_to_canvas (Coord &, Coord &) const;
 	Rect item_to_canvas (Rect const &) const;
+        Duple item_to_canvas (Duple const &) const;
 
 	void raise_to_top ();
 	void raise (int);
diff --git a/libs/canvas/group.cc b/libs/canvas/group.cc
index d12c13169e..34001bc255 100644
--- a/libs/canvas/group.cc
+++ b/libs/canvas/group.cc
@@ -278,6 +278,7 @@ Group::dump (ostream& o) const
 {
 	o << _canvas->indent();
 	o << "Group " << this << " [" << name << ']';
+	o << " @ " << position();
 	o << " Items: " << _items.size();
 	o << " Visible ? " << _visible;
 
@@ -285,6 +286,7 @@ Group::dump (ostream& o) const
 
 	if (bb) {
 		o << endl << _canvas->indent() << "  bbox: " << bb.get();
+		o << endl << _canvas->indent() << "  CANVAS bbox: " << item_to_canvas (bb.get());
 	} else {
 		o << "  bbox unset";
 	}
diff --git a/libs/canvas/item.cc b/libs/canvas/item.cc
index 2c4ec893e7..75a5718271 100644
--- a/libs/canvas/item.cc
+++ b/libs/canvas/item.cc
@@ -67,6 +67,66 @@ Item::item_to_parent (ArdourCanvas::Rect const & r) const
 	return r.translate (_position);
 }
 
+ArdourCanvas::Rect
+Item::item_to_canvas (ArdourCanvas::Rect const & r) const
+{
+	Item const * i = this;
+	Duple offset;
+
+	while (i) {
+		offset = offset.translate (i->position());
+		i = i->parent();
+	}
+
+	return r.translate (offset);
+}
+
+ArdourCanvas::Duple
+Item::item_to_canvas (ArdourCanvas::Duple const & d) const
+{
+	Item const * i = this;
+	Duple offset;
+
+	while (i) {
+		offset = offset.translate (i->position());
+		i = i->parent();
+	}
+
+	return d.translate (offset);
+}
+
+ArdourCanvas::Duple
+Item::canvas_to_item (ArdourCanvas::Duple const & d) const
+{
+	Item const * i = this;
+	Duple offset;
+
+	while (i) {
+		offset = offset.translate (-(i->position()));
+		i = i->parent();
+	}
+
+	return d.translate (offset);
+}
+
+void
+Item::item_to_canvas (Coord& x, Coord& y) const
+{
+	Duple d = item_to_canvas (Duple (x, y));
+		
+	x = d.x;
+	y = d.y;
+}
+
+void
+Item::canvas_to_item (Coord& x, Coord& y) const
+{
+	Duple d = canvas_to_item (Duple (x, y));
+
+	x = d.x;
+	y = d.y;
+}
+
 /** Set the position of this item in the parent's coordinates */
 void
 Item::set_position (Duple p)
@@ -75,6 +135,9 @@ Item::set_position (Duple p)
 	boost::optional<ArdourCanvas::Rect> pre_change_parent_bounding_box;
 
 	if (bbox) {
+		/* see the comment in Canvas::item_moved() to understand
+		 * why we use the parent's bounding box here.
+		 */
 		pre_change_parent_bounding_box = item_to_parent (bbox.get());
 	}
 	
@@ -284,50 +347,6 @@ Item::get_data (string const & key) const
 	return i->second;
 }
 
-void
-Item::item_to_canvas (Coord& x, Coord& y) const
-{
-	Duple d (x, y);
-	Item const * i = this;
-	
-	while (i) {
-		d = i->item_to_parent (d);
-		i = i->_parent;
-	}
-		
-	x = d.x;
-	y = d.y;
-}
-
-void
-Item::canvas_to_item (Coord& x, Coord& y) const
-{
-	Duple d (x, y);
-	Item const * i = this;
-
-	while (i) {
-		d = i->parent_to_item (d);
-		i = i->_parent;
-	}
-
-	x = d.x;
-	y = d.y;
-}
-
-ArdourCanvas::Rect
-Item::item_to_canvas (ArdourCanvas::Rect const & area) const
-{
-	ArdourCanvas::Rect r = area;
-	Item const * i = this;
-
-	while (i) {
-		r = i->item_to_parent (r);
-		i = i->parent ();
-	}
-
-	return r;
-}
-
 void
 Item::set_ignore_events (bool ignore)
 {
@@ -340,6 +359,7 @@ Item::dump (ostream& o) const
 	boost::optional<ArdourCanvas::Rect> bb = bounding_box();
 
 	o << _canvas->indent() << whatami() << ' ' << this;
+	o << " @ " << position();
 	
 #ifdef CANVAS_DEBUG
 	if (!name.empty()) {
@@ -349,6 +369,7 @@ Item::dump (ostream& o) const
 
 	if (bb) {
 		o << endl << _canvas->indent() << "\tbbox: " << bb.get();
+		o << endl << _canvas->indent() << "\tCANVAS bbox: " << item_to_canvas (bb.get());
 	} else {
 		o << " bbox unset";
 	}