Index: /applications/editors/josm/plugins/wmsplugin/src/wmsplugin/WMSLayer.java
===================================================================
--- /applications/editors/josm/plugins/wmsplugin/src/wmsplugin/WMSLayer.java	(revision 22901)
+++ /applications/editors/josm/plugins/wmsplugin/src/wmsplugin/WMSLayer.java	(revision 22902)
@@ -153,4 +153,5 @@
 	public void destroy() {
 		cancelGrabberThreads(false);
+		Main.pref.removePreferenceChangeListener(this);
 	}
 
@@ -640,11 +641,11 @@
 				ois.close();
 				fis.close();
-			    for (GeorefImage[] imgs : images) {
-			        for (GeorefImage img : imgs) {
-			            if (img != null) {
-					        img.setLayer(WMSLayer.this);
-			            }
-			        }
-			    }
+				for (GeorefImage[] imgs : images) {
+					for (GeorefImage img : imgs) {
+						if (img != null) {
+							img.setLayer(WMSLayer.this);
+						}
+					}
+				}
 				settingsChanged = true;
 				mv.repaint();