Sometimes if you're reservation was made on Hyatt.com linked through a conference or event site, the confirmation number does look different even though the rate is eligible. I usually print out the confirmation to take with me on the trip along with airline & car rental confirmations. Usually I don't need it but if any question arises, it's easier to pull out a piece of paper than to find it electronically. I then usually hold on to the airline receipt (and boarding passes) until the miles post. Guess I'll start doing the same with my hotel printouts.