diff -r 26fddf8d65d0 -r 6bc1c1b4473a server/cwzmq.py
--- a/server/cwzmq.py	Thu May 23 14:38:43 2013 +0200
+++ b/server/cwzmq.py	Thu May 23 12:35:02 2013 +0200
@@ -78,7 +78,8 @@
         self._subscribers.append(subscriber)
 
     def publish(self, msg):
-        assert self.publisher is not None, "can't publish without a publisher"
+        if self.publisher is None:
+            return
         self.publisher.send(msg)
 
     def start(self):