diff --git a/src/class_outgoingSynSender.py b/src/class_outgoingSynSender.py
index 11f755de..f154f455 100644
--- a/src/class_outgoingSynSender.py
+++ b/src/class_outgoingSynSender.py
@@ -195,7 +195,7 @@ class outgoingSynSender(threading.Thread, StoppableThread):
                     self.sock.close()
                     return
                 someObjectsOfWhichThisRemoteNodeIsAlreadyAware = {} # This is not necessairly a complete list; we clear it from time to time to save memory.
-                sendDataThreadQueue = Queue.Queue(100) # Used to submit information to the send data thread for this connection. 
+                sendDataThreadQueue = Queue.Queue() # Used to submit information to the send data thread for this connection. 
 
                 sd = sendDataThread(sendDataThreadQueue)
                 sd.setup(self.sock, peer.host, peer.port, self.streamNumber,
diff --git a/src/class_receiveDataThread.py b/src/class_receiveDataThread.py
index 250ae355..6004de5c 100644
--- a/src/class_receiveDataThread.py
+++ b/src/class_receiveDataThread.py
@@ -82,7 +82,7 @@ class receiveDataThread(threading.Thread):
     def run(self):
         logger.debug('receiveDataThread starting. ID ' + str(id(self)) + '. The size of the shared.connectedHostsList is now ' + str(len(shared.connectedHostsList)))
 
-        while True:
+        while state.shutdown == 0:
             dataLen = len(self.data)
             try:
                 ssl = False
@@ -99,12 +99,13 @@ class receiveDataThread(threading.Thread):
                 logger.error ('Timeout occurred waiting for data from ' + str(self.peer) + '. Closing receiveData thread. (ID: ' + str(id(self)) + ')')
                 break
             except socket.error as err:
-                if err.errno == 2 or (sys.platform == 'win32' and err.errno == 10035) or (sys.platform != 'win32' and err.errno == errno.EWOULDBLOCK):
-                    if ssl:
-                        select.select([self.sslSock], [], [])
-                    else:
-                        select.select([self.sock], [], [])
-                    continue
+#                if err.errno == 2 or (sys.platform == 'win32' and err.errno == 10035) or (sys.platform != 'win32' and err.errno == errno.EWOULDBLOCK):
+#                    if ssl:
+#                        select.select([self.sslSock], [], [])
+#                    else:
+#                        select.select([self.sock], [], [])
+#                    logger.error('sock.recv retriable error')
+#                    continue
                 logger.error('sock.recv error. Closing receiveData thread (' + str(self.peer) + ', Thread ID: ' + str(id(self)) + ').' + str(err.errno) + "/" + str(err))
                 if self.initiatedConnection and not self.connectionIsOrWasFullyEstablished:
                     shared.timeOffsetWrongCount += 1
diff --git a/src/class_singleCleaner.py b/src/class_singleCleaner.py
index a4177986..ab16e985 100644
--- a/src/class_singleCleaner.py
+++ b/src/class_singleCleaner.py
@@ -111,7 +111,8 @@ class singleCleaner(threading.Thread, StoppableThread):
                             os._exit(0)
                 shared.knownNodesLock.release()
                 shared.needToWriteKnownNodesToDisk = False
-            self.stop.wait(300)
+            if state.shutdown == 0:
+                self.stop.wait(300)
 
 
 def resendPubkeyRequest(address):
diff --git a/src/class_singleListener.py b/src/class_singleListener.py
index 65c0a8a8..49acc71c 100644
--- a/src/class_singleListener.py
+++ b/src/class_singleListener.py
@@ -134,7 +134,7 @@ class singleListener(threading.Thread, StoppableThread):
                     break
 
             someObjectsOfWhichThisRemoteNodeIsAlreadyAware = {} # This is not necessairly a complete list; we clear it from time to time to save memory.
-            sendDataThreadQueue = Queue.Queue(100) # Used to submit information to the send data thread for this connection.
+            sendDataThreadQueue = Queue.Queue() # Used to submit information to the send data thread for this connection.
             socketObject.settimeout(20)
 
             sd = sendDataThread(sendDataThreadQueue)
diff --git a/src/inventory.py b/src/inventory.py
index d175035d..2bdb3629 100644
--- a/src/inventory.py
+++ b/src/inventory.py
@@ -171,7 +171,8 @@ class PendingDownload(object):
             pass
         for objectHash in unreachableObjects:
             with self.lock:
-                del self.hashes[objectHash]
+                if objectHash in self.hashes:
+                    del self.hashes[objectHash]
 #        logger.debug("Pull took %.3f seconds", time.time() - start)
         return objectHashes