That itinerary did in fact break it, Hyacinthe! Our system wasn't set up properly to recognize MPM (Maximum Permitted Mileage) ticket surcharges (the 5M in the fare construction), and I just fixed it. It should recognize the itinerary if you try it now, though I think the OTAs currently can't book it for the amazing price you've found so far. I just PM'd you asking where you'd like the reward.
Keep them coming, everyone! We've had two people find itineraries that did not work so far.