Index: /applications/editors/josm/plugins/wmsplugin/src/wmsplugin/GeorefImage.java
===================================================================
--- /applications/editors/josm/plugins/wmsplugin/src/wmsplugin/GeorefImage.java	(revision 13666)
+++ /applications/editors/josm/plugins/wmsplugin/src/wmsplugin/GeorefImage.java	(revision 13667)
@@ -27,4 +27,5 @@
     public EastNorth min, max;
     public boolean downloadingStarted;
+    public boolean failed = false;
 
     public GeorefImage(boolean downloadingStarted) {
Index: /applications/editors/josm/plugins/wmsplugin/src/wmsplugin/Grabber.java
===================================================================
--- /applications/editors/josm/plugins/wmsplugin/src/wmsplugin/Grabber.java	(revision 13666)
+++ /applications/editors/josm/plugins/wmsplugin/src/wmsplugin/Grabber.java	(revision 13667)
@@ -53,4 +53,5 @@
         g.drawString(tr("Exception occurred"), 10, height()/2);
         image.image = img;
+        image.failed = true;
         g.setFont(font);
     }
Index: /applications/editors/josm/plugins/wmsplugin/src/wmsplugin/WMSLayer.java
===================================================================
--- /applications/editors/josm/plugins/wmsplugin/src/wmsplugin/WMSLayer.java	(revision 13666)
+++ /applications/editors/josm/plugins/wmsplugin/src/wmsplugin/WMSLayer.java	(revision 13667)
@@ -204,4 +204,5 @@
                 alphaChannel,
                 new JMenuItem(new changeResolutionAction()),
+                new JMenuItem(new reloadErrorTilesAction()),
                 new JMenuItem(new downloadAction()),
                 new JSeparator(),
@@ -237,4 +238,21 @@
             getPPD();
             mv.repaint();
+        }
+    }
+    
+    public class reloadErrorTilesAction extends AbstractAction {
+        public reloadErrorTilesAction() {
+            super(tr("Reload erroneous tiles"));
+        }
+        public void actionPerformed(ActionEvent ev) {
+            for (int x = 0; x < dax; ++x) {
+                for (int y = 0; y < day; ++y) {
+                    GeorefImage img = images[modulo(x,dax)][modulo(y,day)];
+                    img.image = null;
+                    img.downloadingStarted = false;
+                    img.failed = false;
+                    mv.repaint();
+                }
+            }
         }
     }