diff --git a/gtk2_ardour/editor_selection.cc b/gtk2_ardour/editor_selection.cc
index a80d762554..eeabc7ada4 100644
--- a/gtk2_ardour/editor_selection.cc
+++ b/gtk2_ardour/editor_selection.cc
@@ -1512,8 +1512,11 @@ Editor::sensitize_the_right_region_actions (bool because_canvas_crossing)
 				have_inactive_fade_out = true;
 			}
 
-			have_inverted_polarity = ar->scale_amplitude () < 0;
-			have_non_inverted_polarity = ar->scale_amplitude () >= 0;
+			if (ar->scale_amplitude () < 0) {
+				have_inverted_polarity = true;
+			} else {
+				have_non_inverted_polarity = true;
+			}
 		}
 	}
 
@@ -1564,14 +1567,18 @@ Editor::sensitize_the_right_region_actions (bool because_canvas_crossing)
 
 	if (have_audio) {
 
-		if (have_envelope_active && !have_envelope_inactive) {
-			Glib::RefPtr<ToggleAction>::cast_dynamic (_region_actions->get_action("toggle-region-gain-envelope-active"))->set_active ();
+		if (have_envelope_active != have_envelope_inactive) {
+			Glib::RefPtr<ToggleAction>::cast_dynamic (_region_actions->get_action("toggle-region-gain-envelope-active"))->set_active (have_envelope_active);
 		} else if (have_envelope_active && have_envelope_inactive) {
-			// Glib::RefPtr<ToggleAction>::cast_dynamic (_region_actions->get_action("toggle-region-gain-envelope-active"))->set_inconsistent ();
+			// Glib::RefPtr<ToggleAction>::cast_dynamic (_region_actions->get_action("toggle-region-gain-envelope-active"))->set_inconsistent (); // N/A
+			Glib::RefPtr<ToggleAction>::cast_dynamic (_region_actions->get_action("toggle-region-gain-envelope-active"))->set_sensitive (false);
 		}
 
-		if (have_inverted_polarity && !have_non_inverted_polarity) {
-			Glib::RefPtr<ToggleAction>::cast_dynamic (_region_actions->get_action("toggle-region-polarity"))->set_active ();
+		if (have_inverted_polarity != have_non_inverted_polarity) {
+			Glib::RefPtr<ToggleAction>::cast_dynamic (_region_actions->get_action("toggle-region-polarity"))->set_active (have_inverted_polarity);
+		} else if (have_inverted_polarity && have_non_inverted_polarity) {
+			// Glib::RefPtr<ToggleAction>::cast_dynamic (_region_actions->get_action("toggle-region-polarity"))->set_inconsistent (); // N/A
+			Glib::RefPtr<ToggleAction>::cast_dynamic (_region_actions->get_action("toggle-region-polarity"))->set_sensitive (false);
 		}
 
 	} else {