Index: trunk/src/org/openstreetmap/josm/io/ChangesetClosedException.java
===================================================================
--- trunk/src/org/openstreetmap/josm/io/ChangesetClosedException.java	(revision 3561)
+++ trunk/src/org/openstreetmap/josm/io/ChangesetClosedException.java	(revision 3562)
@@ -75,7 +75,7 @@
         if (m.matches()) {
             changesetId = Long.parseLong(m.group(1));
-            // Example: Tue Oct 15 10:00:00 UTC 2009. Always parsed with english locale regardless
+            // Example: "2010-09-07 14:39:41 UTC". Always parsed with US locale regardless
             // of the current locale in JOSM
-            DateFormat formatter = new SimpleDateFormat("EEE MMM dd HH:mm:ss zzz yyyy",Locale.ENGLISH);
+            DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss z", Locale.US);
             try {
                 closedOn = formatter.parse(m.group(2));
Index: trunk/src/org/openstreetmap/josm/tools/ExceptionUtil.java
===================================================================
--- trunk/src/org/openstreetmap/josm/tools/ExceptionUtil.java	(revision 3561)
+++ trunk/src/org/openstreetmap/josm/tools/ExceptionUtil.java	(revision 3562)
@@ -198,7 +198,7 @@
             if (m.matches()) {
                 long changesetId = Long.parseLong(m.group(1));
-                // Example: Tue Oct 15 10:00:00 UTC 2009. Always parsed with english locale, regardless
+                // Example: "2010-09-07 14:39:41 UTC". Always parsed with US locale, regardless
                 // of the current locale in JOSM
-                DateFormat formatter = new SimpleDateFormat("EEE MMM dd HH:mm:ss zzz yyyy", Locale.ENGLISH);
+                DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss z", Locale.US);
                 Date closeDate = null;
                 try {
@@ -249,5 +249,5 @@
                 +"because it has already been closed on {1}.</html>",
                 e.getChangesetId(),
-                dateFormat.format(e.getClosedOn())
+                e.getClosedOn() == null ? "?" : dateFormat.format(e.getClosedOn())
         );
         e.printStackTrace();