diff -Naur rygel-0.21.1.old/src/plugins/external/rygel-external-item-factory.vala rygel-0.21.1/src/plugins/external/rygel-external-item-factory.vala
--- rygel-0.21.1.old/src/plugins/external/rygel-external-item-factory.vala	2013-10-16 12:52:40.000000000 +0200
+++ rygel-0.21.1/src/plugins/external/rygel-external-item-factory.vala	2013-12-17 22:44:52.246598685 +0100
@@ -86,8 +86,8 @@
         if (value != null) {
             var cover_factory = new AlbumArtFactory ();
 
-            music.album_art = yield cover_factory.create ((string) value,
-                                                          service_name);
+            music.album_art = yield cover_factory.create (service_name,
+                                                          (string) value);
         }
 
         this.set_audio_metadata (music, props, service_name);
