Index: trunk/src/org/openstreetmap/josm/gui/dialogs/PropertiesDialog.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/dialogs/PropertiesDialog.java	(revision 1074)
+++ trunk/src/org/openstreetmap/josm/gui/dialogs/PropertiesDialog.java	(revision 1075)
@@ -216,4 +216,9 @@
 			value = null; // delete the key instead
 		}
+        if (newkey.equals("created_by"))
+        {
+            // we don't allow created_by to be changed.
+            return;
+        }
 		if (key.equals(newkey) || value == null)
 			Main.main.undoRedo.add(new ChangePropertyCommand(sel, newkey, value));
@@ -232,5 +237,5 @@
 								map.get(val).add(osm);
 							} else {
-								Vector<OsmPrimitive> v = new 	Vector<OsmPrimitive>();
+								Vector<OsmPrimitive> v = new Vector<OsmPrimitive>();
 								v.add(osm);
 								map.put(val, v);
@@ -322,4 +327,6 @@
 		if (value.equals(""))
 			return;
+        if (key.equals("created_by"))
+            return;
 		Main.main.undoRedo.add(new ChangePropertyCommand(sel, key, value));
 		Main.ds.fireSelectionChanged(sel);