Originally Posted by exerda

Sounds like you were affected by the UA/AC ticket communication issues, where UA makes the reservation, but fouls up sending AC the eticket #, and AC after 3 days cancels the reservation as they don't believe it's been ticketed.

That may also be why UA was so willing to open up their own inventory to accommodate you.

As for the ticket sticking around, you should be fine. So long as the underlying eticket shows a business class award, whether the agent put you in I or ZN shouldn't matter IME. I have had that happen during irrops on my wife's award tickets several times, and have (yet) to have a problem actually flying.