Index: firmware/App/Services/SystemComm.c
===================================================================
diff -u -r07a5add2dff254f7be3699e4efac2b99d3554847 -r9a9d04b84f4345fca87fb14d26f09d497b08aae8
--- firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 07a5add2dff254f7be3699e4efac2b99d3554847)
+++ firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 9a9d04b84f4345fca87fb14d26f09d497b08aae8)
@@ -662,28 +662,25 @@
 
                 if ( msgSize > 0 )
                 {
+                    MESSAGE_WRAPPER_T rcvMsg;
+                    U08 *dataPtr = data+1; // skip over sync byte
+
                     // consume message (+sync byte)
                     msgSize = getFromCommBuffer( MSG_IN_BUFFERS[ i ], data, msgSize + 1 );
-                    // if message data is at least minimum size, convert received message data to a message and add to message queue
-                    if ( msgSize > MESSAGE_OVERHEAD_SIZE )
-                    {
-                        MESSAGE_WRAPPER_T rcvMsg;
-                        U08 *dataPtr = data+1; // skip over sync byte
-
-                        messagesInBuffer = TRUE;
-                        // blank the new message record
-                        blankMessageInWrapper( &rcvMsg );
-                        // copy message header portion of message data to the new message
-                        memcpy( &(rcvMsg.msg.hdr), dataPtr, sizeof(MESSAGE_HEADER_T) );
-                        dataPtr += sizeof(MESSAGE_HEADER_T);
-                        // copy message payload portion of message data to the new message
-                        memcpy( &(rcvMsg.msg.payload), dataPtr, rcvMsg.msg.hdr.payloadLen );
-                        dataPtr += rcvMsg.msg.hdr.payloadLen;
-                        // copy CRC portion of message data to the new message
-                        rcvMsg.crc = *dataPtr;
-                        // add new message to queue for later processing
-                        addToMsgQueue( MSG_Q_IN, &rcvMsg );
-                    } // message is at least as large as minimum size
+                    // convert received message data to a message and add to message queue
+                    messagesInBuffer = TRUE;
+                    // blank the new message record
+                    blankMessageInWrapper( &rcvMsg );
+                    // copy message header portion of message data to the new message
+                    memcpy( &(rcvMsg.msg.hdr), dataPtr, sizeof(MESSAGE_HEADER_T) );
+                    dataPtr += sizeof(MESSAGE_HEADER_T);
+                    // copy message payload portion of message data to the new message
+                    memcpy( &(rcvMsg.msg.payload), dataPtr, rcvMsg.msg.hdr.payloadLen );
+                    dataPtr += rcvMsg.msg.hdr.payloadLen;
+                    // copy CRC portion of message data to the new message
+                    rcvMsg.crc = *dataPtr;
+                    // add new message to queue for later processing
+                    addToMsgQueue( MSG_Q_IN, &rcvMsg );
                 } // looks like there is a complete message in the comm buffer
             } // enough data left in comm buffer to possibly be a complete message
         } // while loop to get all complete messages for each comm buffer
@@ -750,7 +747,7 @@
             // if a minimum sized msg would fit in remaining, continue
             if ( remSize >= MESSAGE_OVERHEAD_SIZE )
             {
-                payloadSize = data[ pos + sizeof( U16 ) ];
+                payloadSize = data[ pos + sizeof( U16 ) + sizeof( U16) ];
                 msgSize = MESSAGE_OVERHEAD_SIZE + payloadSize;
                 // we now know the size of the message - we can now know if full message is contained in buffer
                 if ( msgSize <= remSize )
@@ -889,7 +886,11 @@
         {
             pendingAckList[ i ].used = TRUE;
             _enable_IRQ();
-            pendingAckList[ i ].seqNo = msg->hdr.seqNo &= ~MSG_ACK_BIT;
+            if ( msg->hdr.seqNo < 0 )
+            {
+                msg->hdr.seqNo *= -1;
+            }
+            pendingAckList[ i ].seqNo = msg->hdr.seqNo;
             pendingAckList[ i ].channel = channel;
             pendingAckList[ i ].timeStamp = getMSTimerCount();
             pendingAckList[ i ].retries = MSG_NOT_ACKED_MAX_RETRIES;