diff --git a/gtk2_ardour/instrument_selector.cc b/gtk2_ardour/instrument_selector.cc
index 510fbd8861..2b44ecd296 100644
--- a/gtk2_ardour/instrument_selector.cc
+++ b/gtk2_ardour/instrument_selector.cc
@@ -29,9 +29,10 @@
 using namespace Gtk;
 using namespace ARDOUR;
 
-InstrumentSelector::InstrumentSelector()
-	: _reasonable_synth_id(0)
-	, _gmsynth_id(UINT32_MAX)
+InstrumentSelector::InstrumentSelector (bool allow_none)
+	: _reasonable_synth_id (0)
+	, _gmsynth_id (UINT32_MAX)
+	, _allow_none (allow_none)
 {
 	refill ();
 
@@ -121,11 +122,13 @@ InstrumentSelector::build_instrument_list()
 
 	_instrument_list = ListStore::create(_instrument_list_columns);
 
-	TreeModel::Row row = *(_instrument_list->append());
-	row[_instrument_list_columns.info_ptr] = PluginInfoPtr();
-	row[_instrument_list_columns.name]     = _("-none-");
+	if (_allow_none) {
+		TreeModel::Row row = *(_instrument_list->append());
+		row[_instrument_list_columns.info_ptr] = PluginInfoPtr();
+		row[_instrument_list_columns.name]     = _("-none-");
+	}
 
-	uint32_t n = 1;
+	uint32_t n = _allow_none ? 1 : 0;
 	std::string prev;
 	for (PluginInfoList::const_iterator i = all_plugs.begin(); i != all_plugs.end(); ++i, ++n) {
 		PluginInfoPtr p = *i;
@@ -169,7 +172,7 @@ InstrumentSelector::build_instrument_list()
 			name += " (" + suffix + ")";
 		}
 
-		row = *(_instrument_list->append());
+		TreeModel::Row row = *(_instrument_list->append());
 		row[_instrument_list_columns.name] = name;
 
 		row[_instrument_list_columns.info_ptr] = p;
diff --git a/gtk2_ardour/instrument_selector.h b/gtk2_ardour/instrument_selector.h
index b973ecee7f..15906b50df 100644
--- a/gtk2_ardour/instrument_selector.h
+++ b/gtk2_ardour/instrument_selector.h
@@ -39,7 +39,7 @@ class Editor;
 class InstrumentSelector : public Gtk::ComboBox
 {
 public:
-	InstrumentSelector();
+	InstrumentSelector (bool allow_none = true);
 
 	ARDOUR::PluginInfoPtr selected_instrument () const;
 	std::string selected_instrument_name () const;
@@ -61,6 +61,7 @@ private:
 	InstrumentListColumns        _instrument_list_columns;
 	uint32_t                     _reasonable_synth_id;
 	uint32_t                     _gmsynth_id;
+	bool                         _allow_none;
 	PBD::ScopedConnection        _update_connection;
 };
 
diff --git a/gtk2_ardour/sfdb_ui.cc b/gtk2_ardour/sfdb_ui.cc
index 2cac216a99..8b4fef51dd 100644
--- a/gtk2_ardour/sfdb_ui.cc
+++ b/gtk2_ardour/sfdb_ui.cc
@@ -1761,6 +1761,7 @@ SoundFileOmega::SoundFileOmega (string title, ARDOUR::Session* s,
 				bool persistent,
 				Editing::ImportMode mode_hint)
 	: SoundFileBrowser (title, s, persistent)
+	, instrument_combo (false)
 	, copy_files_btn ( _("Copy files to session"))
 	, smf_tempo_btn (_("Use MIDI Tempo Map (if defined)"))
 	, selected_audio_track_cnt (selected_audio_tracks)