diff --git a/gtk2_ardour/editor.cc b/gtk2_ardour/editor.cc
index 7f2533c909..3318bf91ce 100644
--- a/gtk2_ardour/editor.cc
+++ b/gtk2_ardour/editor.cc
@@ -912,7 +912,7 @@ Editor::zoom_adjustment_changed ()
 		return;
 	}
 
-	double fpu = zoom_range_clock->current_duration() / _visible_canvas_width;
+	framecnt_t fpu = llrintf (zoom_range_clock->current_duration() / _visible_canvas_width);
 	bool clamped = clamp_samples_per_pixel (fpu);
 	
 	if (clamped) {
@@ -1123,7 +1123,7 @@ Editor::map_position_change (framepos_t frame)
 void
 Editor::center_screen (framepos_t frame)
 {
-	double const page = _visible_canvas_width * samples_per_pixel;
+	framecnt_t const page = _visible_canvas_width * samples_per_pixel;
 
 	/* if we're off the page, then scroll.
 	 */
@@ -2263,7 +2263,10 @@ Editor::set_state (const XMLNode& node, int /*version*/)
 	}
 
 	if ((prop = node.property ("zoom"))) {
-		reset_zoom (PBD::atof (prop->value()));
+		/* older versions of ardour used floating point samples_per_pixel */
+		double f = PBD::atof (prop->value());
+		cerr << "LOADED ZOOM from " << prop->value() << " as " << f << endl;
+		reset_zoom (llrintf (f));
 	} else {
 		reset_zoom (samples_per_pixel);
 	}
@@ -2485,7 +2488,8 @@ Editor::get_state ()
 	maybe_add_mixer_strip_width (*node);
 
 	node->add_property ("zoom-focus", enum_2_string (zoom_focus));
-	snprintf (buf, sizeof(buf), "%f", samples_per_pixel);
+
+	snprintf (buf, sizeof(buf), "%" PRId64, samples_per_pixel);
 	node->add_property ("zoom", buf);
 	node->add_property ("snap-to", enum_2_string (_snap_type));
 	node->add_property ("snap-mode", enum_2_string (_snap_mode));
@@ -4115,16 +4119,16 @@ Editor::reset_y_origin (double y)
 }
 
 void
-Editor::reset_zoom (double fpp)
+Editor::reset_zoom (framecnt_t spp)
 {
-	clamp_samples_per_pixel (fpp);
+	clamp_samples_per_pixel (spp);
 
-	if (fpp == samples_per_pixel) {
+	if (spp == samples_per_pixel) {
 		return;
 	}
 
 	pending_visual_change.add (VisualChange::ZoomLevel);
-	pending_visual_change.samples_per_pixel = fpp;
+	pending_visual_change.samples_per_pixel = spp;
 	ensure_visual_change_idle_handler ();
 }
 
@@ -4235,17 +4239,18 @@ Editor::use_visual_state (VisualState& vs)
  *  @param fpu New frames per unit; should already have been clamped so that it is sensible.
  */
 void
-Editor::set_samples_per_pixel (double fpp)
+Editor::set_samples_per_pixel (framecnt_t spp)
 {
+	clamp_samples_per_pixel (spp);
+	samples_per_pixel = spp;
+
 	if (tempo_lines) {
 		tempo_lines->tempo_map_changed();
 	}
 
-	samples_per_pixel = fpp;
-
 	/* convert fpu to frame count */
 
-	framepos_t frames = (framepos_t) floor (samples_per_pixel * _visible_canvas_width);
+	framepos_t frames = samples_per_pixel * _visible_canvas_width;
 
 	if (samples_per_pixel != zoom_range_clock->current_duration()) {
 		zoom_range_clock->set (frames);
diff --git a/gtk2_ardour/editor.h b/gtk2_ardour/editor.h
index f6fa428fad..9533acbb52 100644
--- a/gtk2_ardour/editor.h
+++ b/gtk2_ardour/editor.h
@@ -140,7 +140,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	framepos_t leftmost_sample() const { return leftmost_frame; }
 
 	framecnt_t current_page_samples() const {
-		return (framecnt_t) floor (_visible_canvas_width * samples_per_pixel);
+		return (framecnt_t) _visible_canvas_width * samples_per_pixel;
 	}
 
 	double visible_canvas_height () const {
@@ -216,18 +216,18 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 		*/
 
 		if (pixel >= 0) {
-			return (framepos_t) rint (pixel * samples_per_pixel);
+			return pixel * samples_per_pixel;
 		} else {
 			return 0;
 		}
 	}
 
-	double sample_to_pixel (framepos_t sample) const {
-		return rint (sample / samples_per_pixel);
+        double sample_to_pixel (framepos_t sample) const {
+		return sample / samples_per_pixel;
 	}
 
 	double sample_to_pixel_unrounded (framepos_t sample) const {
-		return sample / samples_per_pixel;
+		return sample / (double) samples_per_pixel;
 	}
 
 	/* selection */
@@ -274,7 +274,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 
 	void               set_zoom_focus (Editing::ZoomFocus);
 	Editing::ZoomFocus get_zoom_focus () const { return zoom_focus; }
-	double             get_current_zoom () const { return samples_per_pixel; }
+	framecnt_t         get_current_zoom () const { return samples_per_pixel; }
         void               cycle_zoom_focus ();
 	void temporal_zoom_step (bool coarser);
 	void tav_zoom_step (bool coarser);
@@ -360,7 +360,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	void reset_x_origin (framepos_t);
 	void reset_x_origin_to_follow_playhead ();
 	void reset_y_origin (double);
-	void reset_zoom (double);
+	void reset_zoom (framecnt_t);
 	void reposition_and_zoom (framepos_t, double);
 
 	framepos_t get_preferred_edit_position (bool ignore_playhead = false, bool use_context_click = false);
@@ -466,7 +466,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	    VisualState (bool with_tracks);
 	    ~VisualState ();
 	    double              y_position;
-	    double              samples_per_pixel;
+	    framecnt_t          samples_per_pixel;
 	    framepos_t          leftmost_frame;
 	    Editing::ZoomFocus  zoom_focus;
 	    GUIObjectState*     gui_state;
@@ -485,12 +485,12 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	void start_visual_state_op (uint32_t n);
 	void cancel_visual_state_op (uint32_t n);
 
-	framepos_t leftmost_frame;
-	double      samples_per_pixel;
+	framepos_t         leftmost_frame;
+        framecnt_t         samples_per_pixel;
 	Editing::ZoomFocus zoom_focus;
 
-	void set_samples_per_pixel (double);
-	bool clamp_samples_per_pixel (double &) const;
+	void set_samples_per_pixel (framecnt_t);
+        bool clamp_samples_per_pixel (framecnt_t &) const;
 
 	Editing::MouseMode mouse_mode;
 	Editing::MouseMode pre_internal_mouse_mode;
@@ -1003,10 +1003,10 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 			YOrigin = 0x4
 		};
 
-		Type pending;
+		Type       pending;
 		framepos_t time_origin;
-		double samples_per_pixel;
-		double y_origin;
+	        framecnt_t samples_per_pixel;
+		double     y_origin;
 
 		int idle_handler_id;
 		/** true if we are currently in the idle handler */
@@ -1190,7 +1190,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	void temporal_zoom_region (bool both_axes);
 	void zoom_to_region (bool both_axes);
 	void temporal_zoom_session ();
-	void temporal_zoom (double scale);
+	void temporal_zoom (framecnt_t samples_per_pixel);
 	void temporal_zoom_by_frame (framepos_t start, framepos_t end);
 	void temporal_zoom_to_frame (bool coarser, framepos_t frame);
 
diff --git a/gtk2_ardour/editor_ops.cc b/gtk2_ardour/editor_ops.cc
index 4037f7a83d..a19fdde5bf 100644
--- a/gtk2_ardour/editor_ops.cc
+++ b/gtk2_ardour/editor_ops.cc
@@ -1331,17 +1331,17 @@ Editor::tav_zoom_smooth (bool coarser, bool force_all)
 }
 
 bool
-Editor::clamp_samples_per_pixel (double& fpp) const
+Editor::clamp_samples_per_pixel (framecnt_t& fpp) const
 {
 	bool clamped = false;
 	
-	if (fpp < 1.0) {
-		fpp = 1.0;
+	if (fpp < 1) {
+		fpp = 1;
 		clamped = true;
 	}
 
 	if (max_framepos / fpp < 800) {
-		fpp = max_framepos / 800.0;
+		fpp = max_framepos / 800;
 		clamped = true;
 	}
 
@@ -1353,19 +1353,19 @@ Editor::temporal_zoom_step (bool coarser)
 {
 	ENSURE_GUI_THREAD (*this, &Editor::temporal_zoom_step, coarser)
 
-	double nfpp = samples_per_pixel;
+	framecnt_t nspp = samples_per_pixel;
 
 	if (coarser) {
-		nfpp = min (9e6, nfpp * 1.61803399);
+		nspp *= 2;
 	} else {
-		nfpp = max (1.0, nfpp / 1.61803399);
+		nspp /= 2;
 	}
 
-	temporal_zoom (nfpp);
+	temporal_zoom (nspp);
 }
 
 void
-Editor::temporal_zoom (double fpp)
+Editor::temporal_zoom (framecnt_t fpp)
 {
 	if (!_session) {
 		return;
@@ -1380,7 +1380,7 @@ Editor::temporal_zoom (double fpp)
 	framepos_t leftmost_after_zoom = 0;
 	framepos_t where;
 	bool in_track_canvas;
-	double nfpp;
+	framecnt_t nfpp;
 	double l;
 
 	clamp_samples_per_pixel (fpp);
@@ -1388,16 +1388,14 @@ Editor::temporal_zoom (double fpp)
 		return;
 	}
 
-	nfpp = fpp;
-	
 	// Imposing an arbitrary limit to zoom out as too much zoom out produces 
 	// segfaults for lack of memory. If somebody decides this is not high enough I
 	// believe it can be raisen to higher values but some limit must be in place.
-	if (nfpp > 8e+08) {
-		nfpp = 8e+08;
-	}
 
-	new_page_size = (framepos_t) floor (_visible_canvas_width * nfpp);
+	nfpp = min (fpp, 8589934592);
+	nfpp = max ((framecnt_t) 1, fpp);
+
+	new_page_size = _visible_canvas_width;
 	half_page_size = new_page_size / 2;
 
 	switch (zoom_focus) {
diff --git a/gtk2_ardour/public_editor.h b/gtk2_ardour/public_editor.h
index 76d888106f..3fc2b878b0 100644
--- a/gtk2_ardour/public_editor.h
+++ b/gtk2_ardour/public_editor.h
@@ -232,7 +232,7 @@ class PublicEditor : public Gtk::Window, public PBD::StatefulDestructible, publi
 	virtual void add_toplevel_controls (Gtk::Container&) = 0;
 	virtual void set_zoom_focus (Editing::ZoomFocus) = 0;
 	virtual Editing::ZoomFocus get_zoom_focus () const = 0;
-	virtual gdouble   get_current_zoom () const = 0;
+	virtual framecnt_t get_current_zoom () const = 0;
 	virtual PlaylistSelector& playlist_selector() const = 0;
 	virtual void clear_playlist (boost::shared_ptr<ARDOUR::Playlist>) = 0;
 	virtual void new_playlists (TimeAxisView*) = 0;