diff -r 9cdd7669dc0b master/fsm_foe.c
--- a/master/fsm_foe.c	Thu Jan 10 17:36:41 2013 +0100
+++ b/master/fsm_foe.c	Tue Jan 22 16:30:55 2013 +0100
@@ -257,7 +257,7 @@
         return -1;
     }
 
-    EC_WRITE_U8 (data, EC_FOE_OPCODE_DATA);    // OpCode = DataBlock req.
+    EC_WRITE_U16 (data, EC_FOE_OPCODE_DATA);    // OpCode = DataBlock req.
     EC_WRITE_U32(data + 2, fsm->tx_packet_no); // PacketNo, Password
 
     memcpy(data + EC_FOE_HEADER_SIZE,
