Index: trunk/src/org/openstreetmap/josm/gui/preferences/SourceEditor.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/preferences/SourceEditor.java	(revision 16963)
+++ trunk/src/org/openstreetmap/josm/gui/preferences/SourceEditor.java	(revision 16964)
@@ -552,5 +552,5 @@
      */
     public void initiallyLoadAvailableSources() {
-        if (!sourcesInitiallyLoaded) {
+        if (!sourcesInitiallyLoaded && !NetworkManager.isOffline(OnlineResource.CACHE_UPDATES)) {
             reloadAvailableSources(availableSourcesUrl, sourceProviders);
         }