diff --git a/external/messenger.py b/external/messenger.py
index 6af2ec2..6b954d4 100755
--- a/external/messenger.py
+++ b/external/messenger.py
@@ -79,16 +79,17 @@ class MessengerBridgeClient(fbchat.Client):
 # ---- SEPARATE THREADS FOR INITIAL SYNC & CLIENT LISTEN ----
 
 class InitialSyncThread(threading.Thread):
-    def __init__(self, client, bridge, *args, **kwargs):
+    def __init__(self, client, bridge, threads, *args, **kwargs):
         super(InitialSyncThread, self).__init__(*args, **kwargs)
 
         self.client = client
         self.bridge = bridge
+        self.threads = threads
 
     def run(self):
-        threads = self.client.fetchThreadList()
         sys.stderr.write("fb thread list: {}\n".format(threads))
-        for thread in threads:
+
+        for thread in self.threads:
             sys.stderr.write("fb thread: {}\n".format(thread))
             if thread.type == ThreadType.GROUP:
                 members = self.client.fetchAllUsersFromThreads([thread])
@@ -100,8 +101,6 @@ class InitialSyncThread(threading.Thread):
 
                 self.send_room_info(thread, members)
                 self.send_room_members(thread, members)
-            elif thread.type == ThreadType.USER:
-                self.bridge.getUserId(thread)
 
             self.backlog_room(thread)
 
@@ -134,25 +133,7 @@ class InitialSyncThread(threading.Thread):
     def send_room_members(self, thread, members):
         for member in members:
             sys.stderr.write("fb thread member: {}\n".format(member))
-            self.bridge.write({
-                "_type": EVENT,
-                "data": {
-                    "type": EVENT_JOIN,
-                    "author": self.bridge.getUserId(member),
-                    "room": thread.uid,
-                }
-            })
-
-            user_info = {
-                "display_name": member.name,
-            }
-            if member.photo is not None:
-                user_info["avatar"] = mediaObjectOfURL(member.photo)
-            self.bridge.write({
-                "_type": USER_INFO_UPDATED,
-                "user": self.bridge.getUserId(member),
-                "data": user_info,
-            })
+            self.bridge.ensureJoined(self.bridge.getUserId(member), thread.uid)
 
     def backlog_room(self, thread):
         prev_last_seen = self.bridge.cache_get("last_seen_%s"%thread.uid)
@@ -194,16 +175,32 @@ class MessengerBridge:
     def __init__(self):
         self.rev_uid = {}
         self.uid_map = {}
+        self.joined_map = {}
 
     def getUserId(self, user):
+        retval = None
         if user.url is not None and not "?" in user.url:
             user_id = user.url.split("/")[-1]
             self.rev_uid[user_id] = user.uid
-            self.uid_map[user.uid] = user_id
+            retval = user_id
         else:
-            self.uid_map[user.uid] = user.uid
+            retval = user.uid
 
-        return self.uid_map[user.uid]
+        if user.uid not in self.uid_map:
+            self.uid_map[user.uid] = retval
+
+            user_info = {
+                "display_name": user.name,
+            }
+            if user.photo is not None:
+                user_info["avatar"] = mediaObjectOfURL(user.photo)
+            self.bridge.write({
+                "_type": USER_INFO_UPDATED,
+                "user": self.bridge.getUserId(user),
+                "data": user_info,
+            })
+
+        return retval
 
     def getUserIdFromUid(self, uid):
         if uid in self.uid_map:
@@ -218,7 +215,6 @@ class MessengerBridge:
         else:
             return user_id
 
-
     def getUserShortName(self, user):
         if user.first_name != None:
             return user.first_name
@@ -281,17 +277,27 @@ class MessengerBridge:
                 email, password = cmd["data"]["email"], cmd["data"]["password"]
                 self.client = MessengerBridgeClient(email=email, password=password, max_tries=1)
 
-            if self.client.isLoggedIn():
-                try:
-                    f = open(client_file, "wb")
-                    pickle.dump(self.client, f)
-                    f.close()
-                except:
-                    pass
+            if not self.client.isLoggedIn():
+                return {"_type": "ret_error", "error": "Unable to login (?)"}
 
-                self.client.setBridge(self)
-                InitialSyncThread(self.client, self).start()
-                ClientListenThread(self.client).start()
+            try:
+                f = open(client_file, "wb")
+                pickle.dump(self.client, f)
+                f.close()
+            except:
+                pass
+
+            self.client.setBridge(self)
+
+            threads = self.client.fetchThreadList()
+            # ensure we have a correct mapping for bridged user IDs to fb uids
+            # (this should be fast)
+            for thread in threads:
+                if thread.type == ThreadType.GROUP:
+                    self.getUserId(thread)
+
+            InitialSyncThread(self.client, self, threads).start()
+            ClientListenThread(self.client).start()
 
         elif ty == CLOSE:
             self.close()
@@ -344,6 +350,19 @@ class MessengerBridge:
     def cache_put(self, key, value):
         self.write({"_type": CACHE_PUT, "key": key, "value": value})
 
+    def ensureJoined(self, userId, room):
+        key = "{}--{}".format(userId, room)
+        if not key in self.joined_map:
+            self.bridge.write({
+                "_type": EVENT,
+                "data": {
+                    "type": EVENT_JOIN,
+                    "author": userId,
+                    "room": room,
+                }
+            })
+            self.joined_map[key] = true
+
     def onMessage(self, thread_id, thread_type, message_object, **kwargs):
         if message_object.author == self.client.uid:
             # Ignore our own messages
@@ -358,6 +377,8 @@ class MessengerBridge:
             }
         if thread_type == ThreadType.GROUP:
             event["room"] = thread_id
+            self.ensureJoined(author, thread_id)
+
         self.write({"_type": EVENT, "data": event})
 
         self.cache_put("last_seen_%s"%thread_id, message_object.uid)
@@ -369,7 +390,6 @@ class MessengerBridge:
     def onTitleChange(self, *args, **kwargs):
         pass
 
-
 if __name__ == "__main__":
     bridge = MessengerBridge()
     bridge.run()