Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -r56b75f69ad7964feb825429db978de284095e0cb -rec40ff879ab8f621fa4cff35f0d69c2804f69c12
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 56b75f69ad7964feb825429db978de284095e0cb)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision ec40ff879ab8f621fa4cff35f0d69c2804f69c12)
@@ -3065,27 +3065,28 @@
     HD_VERSIONS_T payload;
     U08 *payloadPtr = msg.payload;
 
-    U32 len = message->hdr.payloadLen;
+    if ( message->hdr.payloadLen == sizeof( U08 ) + sizeof( U08 ) + sizeof( U08 ) + sizeof( U16 ) + sizeof( U32 ) )
+    {
+        // Get UI version data from this request msg and have it recorded
+        handleUIVersionResponse( message );
 
-    // Get UI version data from this request msg and have it recorded
-    handleUIVersionResponse( message );
+        // Populate payload for response
+        payload.major = (U08)HD_VERSION_MAJOR;
+        payload.minor = (U08)HD_VERSION_MINOR;
+        payload.micro = (U08)HD_VERSION_MICRO;
+        payload.build = (U16)HD_VERSION_BUILD;
+        payload.compatibilityRev = (U32)SW_COMPATIBILITY_REV;
+        getFPGAVersions( &payload.fpgaId, &payload.fpgaMajor, &payload.fpgaMinor, &payload.fpgaLab );
 
-    // Populate payload for response
-    payload.major = (U08)HD_VERSION_MAJOR;
-    payload.minor = (U08)HD_VERSION_MINOR;
-    payload.micro = (U08)HD_VERSION_MICRO;
-    payload.build = (U16)HD_VERSION_BUILD;
-    payload.compatibilityRev = (U32)SW_COMPATIBILITY_REV;
-    getFPGAVersions( &payload.fpgaId, &payload.fpgaMajor, &payload.fpgaMinor, &payload.fpgaLab );
+        // Create a message record
+        blankMessage( &msg );
+        msg.hdr.msgID = MSG_ID_HD_VERSION;
+        msg.hdr.payloadLen = sizeof( HD_VERSIONS_T );
 
-    // Create a message record
-    blankMessage( &msg );
-    msg.hdr.msgID = MSG_ID_HD_VERSION;
-    msg.hdr.payloadLen = sizeof( HD_VERSIONS_T );
+        // Fill message payload
+        memcpy( payloadPtr, &payload, sizeof( HD_VERSIONS_T ) );
+    }
 
-    // Fill message payload
-    memcpy( payloadPtr, &payload, sizeof( HD_VERSIONS_T ) );
-
     // Serialize the message (w/ sync, CRC, and appropriate CAN padding) and add serialized message data to appropriate comm buffer
     serializeMessage( msg, COMM_BUFFER_OUT_CAN_HD_2_UI, ACK_REQUIRED );
 }
@@ -3139,7 +3140,7 @@
     msg.hdr.payloadLen = MAX_TOP_LEVEL_SN_CHARS + 1;
 
     // Fill message payload
-    memcpy( payloadPtr, &system.topLevelSN, MAX_TOP_LEVEL_SN_CHARS );
+    memcpy( payloadPtr, &system.topLevelSN, sizeof( U08 ) * MAX_TOP_LEVEL_SN_CHARS );
     payloadPtr += MAX_TOP_LEVEL_SN_CHARS;
     *payloadPtr = 0;