Index: applications/editors/josm/plugins/slippymap/src/org/openstreetmap/josm/plugins/slippymap/SlippyMapLayer.java
===================================================================
--- applications/editors/josm/plugins/slippymap/src/org/openstreetmap/josm/plugins/slippymap/SlippyMapLayer.java	(revision 19050)
+++ applications/editors/josm/plugins/slippymap/src/org/openstreetmap/josm/plugins/slippymap/SlippyMapLayer.java	(revision 19070)
@@ -48,4 +48,5 @@
 import org.openstreetmap.josm.gui.layer.Layer;
 import org.openstreetmap.josm.tools.ImageProvider;
+import org.openstreetmap.josm.gui.MapView.LayerChangeListener;
 
 /**
@@ -252,5 +253,5 @@
                 });
 
-                addLayerChangeListener(new LayerChangeListener() {
+                MapView.addLayerChangeListener(new LayerChangeListener() {
                     public void activeLayerChange(Layer oldLayer, Layer newLayer) {
                     	//
@@ -262,5 +263,6 @@
 
                     public void layerRemoved(Layer oldLayer) {
-                        Main.pref.addPreferenceChangeListener(SlippyMapLayer.this);
+                    	MapView.removeLayerChangeListener(this);
+                        Main.pref.removePreferenceChangeListener(SlippyMapLayer.this);
                     }
                 });