diff --git a/IPython/parallel/controller/hub.py b/IPython/parallel/controller/hub.py
index f557214..4e2e5a8 100644
--- a/IPython/parallel/controller/hub.py
+++ b/IPython/parallel/controller/hub.py
@@ -457,7 +457,7 @@ class Hub(SessionFactory):
     def dispatch_monitor_traffic(self, msg):
         """all ME and Task queue messages come through here, as well as
         IOPub traffic."""
-        self.log.debug("monitor traffic: %r", msg[:2])
+        self.log.debug("monitor traffic: %r", msg[0])
         switch = msg[0]
         try:
             idents, msg = self.session.feed_identities(msg[1:])
diff --git a/IPython/parallel/controller/scheduler.py b/IPython/parallel/controller/scheduler.py
index bf9a32e..6349de2 100644
--- a/IPython/parallel/controller/scheduler.py
+++ b/IPython/parallel/controller/scheduler.py
@@ -191,6 +191,8 @@ class TaskScheduler(SessionFactory):
 
     def start(self):
         self.engine_stream.on_recv(self.dispatch_result, copy=False)
+        self.client_stream.on_recv(self.dispatch_submission, copy=False)
+
         self._notification_handlers = dict(
             registration_notification = self._register_engine,
             unregistration_notification = self._unregister_engine
@@ -247,8 +249,7 @@ class TaskScheduler(SessionFactory):
         self.completed[uid] = set()
         self.failed[uid] = set()
         self.pending[uid] = {}
-        if len(self.targets) == 1:
-            self.resume_receiving()
+
         # rescan the graph:
         self.update_graph(None)
 
@@ -256,7 +257,7 @@ class TaskScheduler(SessionFactory):
         """Existing engine with ident `uid` became unavailable."""
         if len(self.targets) == 1:
             # this was our only engine
-            self.stop_receiving()
+            pass
 
         # handle any potentially finished tasks:
         self.engine_stream.flush()
@@ -439,6 +440,11 @@ class TaskScheduler(SessionFactory):
 
     def maybe_run(self, msg_id, raw_msg, targets, after, follow, timeout):
         """check location dependencies, and run if they are met."""
+        self.log.debug("Attempting to assign task %s", msg_id)
+        if not self.targets:
+            # no engines, definitely can't run
+            return False
+        
         blacklist = self.blacklist.setdefault(msg_id, set())
         if follow or targets or blacklist or self.hwm:
             # we need a can_run filter