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 16459)
+++ /applications/editors/josm/plugins/slippymap/src/org/openstreetmap/josm/plugins/slippymap/SlippyMapLayer.java	(revision 16460)
@@ -265,4 +265,5 @@
             t.dropImage();
             nr_to_drop--;
+            tileStorage.remove(t.getKey());
         }
     }
Index: /applications/editors/josm/plugins/slippymap/src/org/openstreetmap/josm/plugins/slippymap/SlippyMapTile.java
===================================================================
--- /applications/editors/josm/plugins/slippymap/src/org/openstreetmap/josm/plugins/slippymap/SlippyMapTile.java	(revision 16459)
+++ /applications/editors/josm/plugins/slippymap/src/org/openstreetmap/josm/plugins/slippymap/SlippyMapTile.java	(revision 16460)
@@ -182,3 +182,7 @@
         return (this.x == other.x && this.y == other.y && this.z == other.z);
     }
+    SlippyMapKey getKey()
+    {
+	    return new SlippyMapKey(x, y, z);
+    }
 }