diff --git a/telethon/network/mtproto_sender.py b/telethon/network/mtproto_sender.py
index 95a64624..d1ccca48 100644
--- a/telethon/network/mtproto_sender.py
+++ b/telethon/network/mtproto_sender.py
@@ -106,7 +106,9 @@ class MtProtoSender:
 
             # We're done receiving, remove the request from pending, if any
             if request:
-                self._pending_receive.remove(request)
+                try:
+                    self._pending_receive.remove(request)
+                except ValueError: pass
 
             self._logger.info('Request result received')
         self._logger.debug('receive() released the lock')
@@ -184,7 +186,11 @@ class MtProtoSender:
         return message, remote_msg_id, remote_sequence
 
     def _process_msg(self, msg_id, sequence, reader, updates):
-        """Processes and handles a Telegram message"""
+        """Processes and handles a Telegram message.
+
+           Returns True if the message was handled correctly and doesn't
+           need to be skipped. Returns False otherwise.
+        """
 
         # TODO Check salt, session_id and sequence_number
         self._need_confirmation.append(msg_id)
@@ -222,7 +228,7 @@ class MtProtoSender:
                         self._logger.info('Message ack confirmed a request')
                         r.confirm_received = True
 
-            return False
+            return True
 
         # If the code is not parsed manually, then it was parsed by the code generator!
         # In this case, we will simply treat the incoming TLObject as an Update,
@@ -235,7 +241,7 @@ class MtProtoSender:
                 self._logger.debug('Read update for %s', repr(result))
                 updates.append(result)
 
-            return False
+            return True
 
         self._logger.warning('Unknown message: {}'.format(hex(code)))
         return False
@@ -257,7 +263,7 @@ class MtProtoSender:
             request.confirm_received = True
         except StopIteration: pass
 
-        return False
+        return True
 
     def _handle_container(self, msg_id, sequence, reader, updates):
         self._logger.debug('Handling container')
@@ -275,7 +281,7 @@ class MtProtoSender:
                     inner_msg_id, sequence, reader, updates):
                 reader.set_position(begin_position + inner_length)
 
-        return False
+        return True
 
     def _handle_bad_server_salt(self, msg_id, sequence, reader):
         self._logger.debug('Handling bad server salt')
@@ -310,6 +316,7 @@ class MtProtoSender:
             self.session.save()
             self._logger.warning('Read Bad Message error: ' + str(error))
             self._logger.info('Attempting to use the correct time offset.')
+            return True
         else:
             raise error
 
@@ -343,26 +350,22 @@ class MtProtoSender:
 
             raise error
         else:
-            if not request:
-                raise ValueError(
-                    'The request needed to read this RPC result was not '
-                    'found (possibly called receive() from another thread).')
-
-            self._logger.debug('Reading request response')
-            if inner_code == 0x3072cfa1:  # GZip packed
-                unpacked_data = gzip.decompress(reader.tgread_bytes())
-                with BinaryReader(unpacked_data) as compressed_reader:
-                    request.on_response(compressed_reader)
-            else:
-                reader.seek(-4)
-                if request_id == request.msg_id:
-                    request.on_response(reader)
+            if request:
+                self._logger.debug('Reading request response')
+                if inner_code == 0x3072cfa1:  # GZip packed
+                    unpacked_data = gzip.decompress(reader.tgread_bytes())
+                    with BinaryReader(unpacked_data) as compressed_reader:
+                        request.on_response(compressed_reader)
                 else:
-                    # If it's really a result for RPC from previous connection
-                    # session, it will be skipped by the handle_container()
-                    self._logger.warning(
-                        'RPC result found for unknown request '
-                        '(maybe from previous connection session)')
+                    reader.seek(-4)
+                    request.on_response(reader)
+
+                return True
+            else:
+                # If it's really a result for RPC from previous connection
+                # session, it will be skipped by the handle_container()
+                self._logger.warning('Lost request will be skipped.')
+                return False
 
     def _handle_gzip_packed(self, msg_id, sequence, reader, updates):
         self._logger.debug('Handling gzip packed data')