fix bug where stations before selection not added to table

nexus/nexus.py

@@ -1302,6 +1302,7 @@ class StationWidget(WidgetBase, *load_ui("StationWidget.ui")):
                              "DLgain": dialog.gainCB.isChecked(),
                              "Stype": dialog.sensorCB.isChecked()}
             self.update_inventory(dialog.selected_stations, checked_boxes)
+        self.stat_node_to_obj_map = {}
 
     def update_inventory(self, stations, checked_boxes):
         for stat in stations:
@@ -1322,7 +1323,8 @@ class StationWidget(WidgetBase, *load_ui("StationWidget.ui")):
         Get all stations from inventory to
         add to Station Select Dialogue
         """
-        net = self._data_mapper.rootIndex()
+        # get top most network
+        net = self._model.index(0, 0, QtCore.QModelIndex())
         self.stat_node_to_obj_map = {}
         stations = []
         net_row = 0