Index: /trunk/src/org/openstreetmap/josm/Main.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/Main.java	(revision 12506)
+++ /trunk/src/org/openstreetmap/josm/Main.java	(revision 12507)
@@ -1159,5 +1159,5 @@
      */
     public static boolean addAndFireMapFrameListener(MapFrameListener listener) {
-        return mainPanel.addAndFireMapFrameListener(listener);
+        return mainPanel != null && mainPanel.addAndFireMapFrameListener(listener);
     }
 
@@ -1170,5 +1170,5 @@
      */
     public static boolean addMapFrameListener(MapFrameListener listener) {
-        return mainPanel.addMapFrameListener(listener);
+        return mainPanel != null && mainPanel.addMapFrameListener(listener);
     }
 
@@ -1180,5 +1180,5 @@
      */
     public static boolean removeMapFrameListener(MapFrameListener listener) {
-        return mainPanel.removeMapFrameListener(listener);
+        return mainPanel != null && mainPanel.removeMapFrameListener(listener);
     }