I think you are right, NW seems to have screwed up our infant in arms ticket too. We are currently in SE Asia with my wife and daughter on an award ticket (infant in arms). I was positive the thing was ticketed correctly, so when we were leaving Seattle and the GA started asking question about the infant ticket I more or less said "why don't you fix it and we'll be on the plane if you have any questions...." We got settled in our seats and I didnt hear anything more so I assumed it was all OK.

Imagine my surprise when we called from Indonesia yesterday to change my wife's return ticket to a few days later and they ran into major problems with the infant part of the ticket. Luckily I got thru to a NW platinum agent who knew the NW rule (taxes only) and didn't try to charge me 10% of the fare. I suspect if we had shown up at Changi for our original flight on Sunday that we would have been forced to pay the 10% fee. It took nearly an hour to get this sorted out... Now that I look back at the old reservation, I can see that there was no actual ticket # attached next to my daughter's name (although she did appear on the reservation). Now she does have a ticket #, so I guess that is something to look for.