Index: trunk/src/org/openstreetmap/josm/gui/mappaint/MapImage.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/mappaint/MapImage.java	(revision 6710)
+++ trunk/src/org/openstreetmap/josm/gui/mappaint/MapImage.java	(revision 6711)
@@ -37,5 +37,5 @@
 
     private boolean temporary;
-    private Image disabledImg;
+    private Image disabledImgCache;
 
     public MapImage(String name, StyleSource source) {
@@ -45,10 +45,10 @@
 
     public Image getDisabled() {
-        if (disabledImg != null)
-            return disabledImg;
+        if (disabledImgCache != null)
+                return disabledImgCache;
         if (img == null)
             getImage(); // fix #7498 ?
-        disabledImg = GuiHelper.getDisabledImage(img);
-        return disabledImg;
+        disabledImgCache = GuiHelper.getDisabledImage(img);
+        return disabledImgCache;
     }
 
@@ -76,4 +76,5 @@
                             }
                             if (temporary) {
+                                disabledImgCache = null;
                                 Main.map.mapView.preferenceChanged(null); // otherwise repaint is ignored, because layer hasn't changed
                                 Main.map.mapView.repaint();