Index: trunk/src/org/openstreetmap/josm/gui/conflict/pair/properties/PropertiesMerger.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/conflict/pair/properties/PropertiesMerger.java	(revision 8784)
+++ trunk/src/org/openstreetmap/josm/gui/conflict/pair/properties/PropertiesMerger.java	(revision 8785)
@@ -404,5 +404,5 @@
         @Override
         public void update(Observable o, Object arg) {
-            setEnabled(model.hasCoordConflict() && !model.isDecidedCoord());
+            setEnabled(model.hasCoordConflict() && !model.isDecidedCoord() && model.getMyCoords() != null);
         }
     }
@@ -421,5 +421,5 @@
         @Override
         public void update(Observable o, Object arg) {
-            setEnabled(model.hasCoordConflict() && !model.isDecidedCoord());
+            setEnabled(model.hasCoordConflict() && !model.isDecidedCoord() && model.getTheirCoords() != null);
         }
     }