Index: applications/editors/josm/plugins/czechaddress/src/org/openstreetmap/josm/plugins/czechaddress/gui/FactoryDialog.java
===================================================================
--- applications/editors/josm/plugins/czechaddress/src/org/openstreetmap/josm/plugins/czechaddress/gui/FactoryDialog.java	(revision 33250)
+++ applications/editors/josm/plugins/czechaddress/src/org/openstreetmap/josm/plugins/czechaddress/gui/FactoryDialog.java	(revision 33251)
@@ -87,4 +87,10 @@
         houseList.setModel(houseModel);
         houseList.setCellRenderer(new HouseListRenderer());
+    }
+
+    @Override
+    public void destroy() {
+        super.destroy();
+        singleton = null;
     }