diff --git a/src/bitmessagemain.py b/src/bitmessagemain.py
index 93acfa19..be96fc6d 100755
--- a/src/bitmessagemain.py
+++ b/src/bitmessagemain.py
@@ -303,6 +303,10 @@ class receiveDataThread(threading.Thread):
             shared.printLock.acquire()
             print 'Could not delete', self.HOST, 'from shared.connectedHostsList.', err
             shared.printLock.release()
+        try:
+            del numberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHavePerPeer[self.HOST]
+        except:
+            pass
         shared.UISignalQueue.put(('updateNetworkStatusTab','no data'))
         shared.printLock.acquire()
         print 'The size of the connectedHostsList is now:', len(shared.connectedHostsList)
@@ -386,15 +390,24 @@ class receiveDataThread(threading.Thread):
                                     shared.printLock.acquire()
                                     print '(concerning', self.HOST + ')', 'number of objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave is now', len(self.objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave)
                                     shared.printLock.release()
+                                    try:
+                                        del numberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHavePerPeer[self.HOST]
+                                    except:
+                                        pass
                                 break
                             if len(self.objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave) == 0:
                                 shared.printLock.acquire()
                                 print '(concerning', self.HOST + ')', 'number of objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave is now', len(self.objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave)
                                 shared.printLock.release()
+                                try:
+                                    del numberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHavePerPeer[self.HOST]
+                                except:
+                                    pass
                         if len(self.objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave) > 0:
                             shared.printLock.acquire()
                             print '(concerning', self.HOST + ')', 'number of objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave is now', len(self.objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave)
                             shared.printLock.release()
+                            numberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHavePerPeer[self.HOST] = len(self.objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave)
                         if len(self.ackDataThatWeHaveYetToSend) > 0:
                             self.data = self.ackDataThatWeHaveYetToSend.pop()
                     self.processData()
@@ -1489,11 +1502,26 @@ class receiveDataThread(threading.Thread):
 
     #We have received an inv message
     def recinv(self,data):
+        totalNumberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave = 0
+        print 'number of keys(hosts) in numberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHavePerPeer:', len(numberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHavePerPeer)
+        for key, value in numberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHavePerPeer.items():
+            totalNumberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave += value
+        print 'totalNumberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave = ', totalNumberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave
+        """if totalNumberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave > 200000:
+            shared.printLock.acquire()
+            print 'We already have', totalNumberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave, 'items yet to retrieve from peers. Ignoring this inv message.'
+            shared.printLock.release()
+            return"""
         numberOfItemsInInv, lengthOfVarint = decodeVarint(data[:10])
         if len(data) < lengthOfVarint + (numberOfItemsInInv * 32):
             print 'inv message doesn\'t contain enough data. Ignoring.'
             return
         if numberOfItemsInInv == 1: #we'll just request this data from the person who advertised the object.
+            if totalNumberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave > 200000 and len(self.objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave) > 1000:
+                shared.printLock.acquire()
+                print 'We already have', totalNumberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave, 'items yet to retrieve from peers and over 1000 from this node in particular. Ignoring this inv message.'
+                shared.printLock.release()            
+                return
             self.objectsOfWhichThisRemoteNodeIsAlreadyAware[data[lengthOfVarint:32+lengthOfVarint]] = 0
             if data[lengthOfVarint:32+lengthOfVarint] in shared.inventory:
                 shared.printLock.acquire()
@@ -1507,8 +1535,14 @@ class receiveDataThread(threading.Thread):
             print 'inv message lists', numberOfItemsInInv, 'objects.'
             for i in range(numberOfItemsInInv): #upon finishing dealing with an incoming message, the receiveDataThread will request a random object from the peer. This way if we get multiple inv messages from multiple peers which list mostly the same objects, we will make getdata requests for different random objects from the various peers.
                 if len(data[lengthOfVarint+(32*i):32+lengthOfVarint+(32*i)]) == 32: #The length of an inventory hash should be 32. If it isn't 32 then the remote node is either badly programmed or behaving nefariously.
+                    if totalNumberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave > 200000 and len(self.objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave) > 1000:
+                        shared.printLock.acquire()
+                        print 'We already have', totalNumberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave, 'items yet to retrieve from peers and over',len(self.objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave),'from this node in particular. Ignoring the rest of this inv message.'
+                        shared.printLock.release()
+                        break
                     self.objectsOfWhichThisRemoteNodeIsAlreadyAware[data[lengthOfVarint+(32*i):32+lengthOfVarint+(32*i)]] = 0
                     self.objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave[data[lengthOfVarint+(32*i):32+lengthOfVarint+(32*i)]] = 0
+            numberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHavePerPeer[self.HOST] = len(self.objectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHave)
 
 
     #Send a getdata message to our peer to request the object with the given hash
@@ -2535,6 +2569,12 @@ class singleCleaner(threading.Thread):
                 shared.sqlSubmitQueue.put(t)
                 queryreturn = shared.sqlReturnQueue.get()
                 for row in queryreturn:
+                    if len(row) < 5:
+                        shared.printLock.acquire()
+                        sys.stderr.write('Something went wrong in the singleCleaner thread: a query did not return the requested fields. '+repr(row))
+                        time.sleep(3)
+                        shared.printLock.release()
+                        break
                     toaddress, toripe, fromaddress, subject, message, ackdata, lastactiontime, status, pubkeyretrynumber, msgretrynumber = row
                     if status == 'findingpubkey':
                         if int(time.time()) - lastactiontime > (maximumAgeOfAnObjectThatIAmWillingToAccept * (2 ** (pubkeyretrynumber))):
@@ -3880,6 +3920,7 @@ neededPubkeys = {}
 successfullyDecryptMessageTimings = [] #A list of the amounts of time it took to successfully decrypt msg messages
 apiAddressGeneratorReturnQueue = Queue.Queue() #The address generator thread uses this queue to get information back to the API thread.
 alreadyAttemptedConnectionsListResetTime = int(time.time()) #used to clear out the alreadyAttemptedConnectionsList periodically so that we will retry connecting to hosts to which we have already tried to connect.
+numberOfObjectsThatWeHaveYetToCheckAndSeeWhetherWeAlreadyHavePerPeer = {}
 
 if useVeryEasyProofOfWorkForTesting:
     shared.networkDefaultProofOfWorkNonceTrialsPerByte = int(shared.networkDefaultProofOfWorkNonceTrialsPerByte / 16)