Index: applications/editors/josm/plugins/geochat/src/geochat/ChatServerConnection.java
===================================================================
--- applications/editors/josm/plugins/geochat/src/geochat/ChatServerConnection.java	(revision 30261)
+++ applications/editors/josm/plugins/geochat/src/geochat/ChatServerConnection.java	(revision 30262)
@@ -402,8 +402,8 @@
                 try {
                 	JsonObject msg = messages.getJsonObject(i);
-                    long id = msg.getJsonNumber("id").longValue();
-                    double lat = msg.getJsonNumber("lat").doubleValue();
-                    double lon = msg.getJsonNumber("lon").doubleValue();
-                    long timeStamp = msg.getJsonNumber("timestamp").longValue();
+                    long id = Long.parseLong(msg.getString("id"));
+                    double lat = Double.parseDouble(msg.getString("lat"));
+                    double lon = Double.parseDouble(msg.getString("lon"));
+                    long timeStamp = Long.parseLong(msg.getString("timestamp"));
                     String author = msg.getString("author");
                     String message = msg.getString("message");
@@ -428,6 +428,6 @@
                 	JsonObject user = users.getJsonObject(i);
                     String name = user.getString("user");
-                    double lat = user.getJsonNumber("lat").doubleValue();
-                    double lon = user.getJsonNumber("lon").doubleValue();
+                    double lat = Double.parseDouble(user.getString("lat"));
+                    double lon = Double.parseDouble(user.getString("lon"));
                     result.put(name, new LatLon(lat, lon));
                 } catch( JsonException e ) {
Index: applications/editors/josm/plugins/geochat/src/geochat/GeoChatPanel.java
===================================================================
--- applications/editors/josm/plugins/geochat/src/geochat/GeoChatPanel.java	(revision 30261)
+++ applications/editors/josm/plugins/geochat/src/geochat/GeoChatPanel.java	(revision 30262)
@@ -226,7 +226,12 @@
         Main.pref.put("geochat.username", userName);
         if( gcPanel.getComponentCount() == 1 ) {
-            gcPanel.remove(0);
-            gcPanel.add(tabs, BorderLayout.CENTER);
-            gcPanel.add(input, BorderLayout.SOUTH);
+        	GuiHelper.runInEDTAndWait(new Runnable() {
+				@Override
+				public void run() {
+		            gcPanel.remove(0);
+		            gcPanel.add(tabs, BorderLayout.CENTER);
+		            gcPanel.add(input, BorderLayout.SOUTH);
+				}
+			});
         }
         updateTitleAlarm();