Index: /applications/editors/josm/plugins/validator/src/org/openstreetmap/josm/plugins/validator/ErrorLayer.java
===================================================================
--- /applications/editors/josm/plugins/validator/src/org/openstreetmap/josm/plugins/validator/ErrorLayer.java	(revision 4085)
+++ /applications/editors/josm/plugins/validator/src/org/openstreetmap/josm/plugins/validator/ErrorLayer.java	(revision 4086)
@@ -17,8 +17,8 @@
 import org.openstreetmap.josm.data.osm.visitor.BoundingXYVisitor;
 import org.openstreetmap.josm.gui.MapView;
-import org.openstreetmap.josm.gui.MapView.LayerChangeListener;
 import org.openstreetmap.josm.gui.dialogs.LayerListDialog;
 import org.openstreetmap.josm.gui.dialogs.LayerListPopup;
 import org.openstreetmap.josm.gui.layer.Layer;
+import org.openstreetmap.josm.gui.layer.Layer.LayerChangeListener;
 import org.openstreetmap.josm.plugins.validator.util.Bag;
 import org.openstreetmap.josm.tools.ImageProvider;
@@ -38,5 +38,5 @@
     {
 		super(name);
-        Main.map.mapView.addLayerChangeListener(this); 
+        Layer.listeners.add(this); 
 	}
 
Index: /applications/editors/josm/plugins/validator/src/org/openstreetmap/josm/plugins/validator/OSMValidatorPlugin.java
===================================================================
--- /applications/editors/josm/plugins/validator/src/org/openstreetmap/josm/plugins/validator/OSMValidatorPlugin.java	(revision 4085)
+++ /applications/editors/josm/plugins/validator/src/org/openstreetmap/josm/plugins/validator/OSMValidatorPlugin.java	(revision 4086)
@@ -14,7 +14,7 @@
 import org.openstreetmap.josm.actions.UploadAction.UploadHook;
 import org.openstreetmap.josm.gui.MapFrame;
-import org.openstreetmap.josm.gui.MapView.LayerChangeListener;
 import org.openstreetmap.josm.gui.layer.Layer;
 import org.openstreetmap.josm.gui.layer.OsmDataLayer;
+import org.openstreetmap.josm.gui.layer.Layer.LayerChangeListener;
 import org.openstreetmap.josm.gui.preferences.PreferenceSetting;
 import org.openstreetmap.josm.plugins.Plugin;
@@ -82,8 +82,8 @@
 	        newFrame.addToggleDialog(validationDialog);
             Main.main.addLayer(new ErrorLayer(tr("Validation errors")));
-            Main.map.mapView.addLayerChangeListener(this); 
+            Layer.listeners.add(this); 
 		}
 		else
-            oldFrame.mapView.removeLayerChangeListener(this); 
+            Layer.listeners.remove(this); 
         
         // Add/Remove the upload hook