Index: firmware/App/Services/SystemComm.c
===================================================================
diff -u -r05b4d416b6bd5e7af4347f112a20f9f81a257064 -r3e525c0567dd0b7d2153b751169d0ae17648e117
--- firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 05b4d416b6bd5e7af4347f112a20f9f81a257064)
+++ firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 3e525c0567dd0b7d2153b751169d0ae17648e117)
@@ -49,7 +49,7 @@
 #define MAX_COMM_CRC_FAILURE_WINDOW_MS  (10 * SEC_PER_MIN * MS_PER_SECOND)
 
 #define MSG_NOT_ACKED_TIMEOUT_MS    ( MS_PER_SECOND * 1 )
-#define MSG_NOT_ACKED_MAX_RETRIES   5
+#define MSG_NOT_ACKED_MAX_RETRIES   3
 #define PENDING_ACK_LIST_SIZE       25
 
 #pragma pack(push,1)
@@ -788,15 +788,25 @@
             if ( message.crc == crc8( (U08*)(&message), sizeof(MESSAGE_HEADER_T) + message.msg.hdr.payloadLen ) )
             {
 #ifndef ACK_NOT_IMPLEMENTED
-                // if ACK,
+                // if ACK, mark pending message ACK'd
                 if ( MSG_ID_ACK == message.msg.hdr.msgID )
                 {
                     matchACKtoPendingACKList( message.msg.hdr.seqNo );
                 }
                 else
 #endif
                 {
-                    processReceivedMessage( &message.msg );
+#ifndef ACK_NOT_IMPLEMENTED
+                    // if received message requires ACK, queue one up
+                    if ( message.msg.hdr.seqNo < 0 )
+                    {
+                        sendACKMsg( &message.msg );
+                    }
+                    else
+#endif
+                    {   // otherwise, process the received message
+                        processReceivedMessage( &message.msg );
+                    }
                 }
             }
             else // CRC failed
@@ -988,14 +998,6 @@
 {
     U16 msgID = message->hdr.msgID;
 
-#ifndef ACK_NOT_IMPLEMENTED
-    // if received message requires ACK, queue one up
-    if ( message->hdr.seqNo < 0 )
-    {
-        sendACKMsg( message );
-    }
-#endif
-
     // handle any messages from other sub-systems
     switch ( msgID )
     {