Had the same code for this flight along with a D code.
08OCT2004
NW 8499 KL 1823 Y/M AMS - TXL - D (Coupon refunded or exchanged.)
NW 8499 NW 8499 B/B AMS - TXL - S (Mileage too soon to post.)
Both are new for me. D code posted on the 10th, and the S code today. Figure it will take a few days to sort out and I'll get my miles then. Never fails.
BTW, do not forget to have a NW agent re-enter your WP# on your current reservations so your upgrades come 3 days before departure.