I didn't double up on anything, the online reservations doesn't let you double book either, for instance, today I booked Via Napoli and already had a reservation for that night, it asks you if you want to cancel the existing reservation before it'll confirm the new one. and it's easy to cancel online, unfortunately I won't be carrying around a laptop with me. However, before I was making my ADR's online, I was calling when I wanted to make changes and sometimes it can be a 20 minute call just to cancel a reservation. If you read the Unofficial Guide it explains that an ADR is not a real reservation, it doesn't mean they hold a table, it just puts you on a list to get the next available table once you show up (and after everyone else that was waiting before you for a table with an ADR.) I see what you're saying about someone else not being able to make a reservation if I take that time slot. but it's also one additional table that would be available for a customer without a reservation. I'm going to try to make it to all of my reservations but if for some reason I miss one and don't cancel a few hours before, does Disney hold that against you? I'm not just trying to fill all available meal times with reservations, I just made reservations for the places I want to go. I'm just wondering if we realize 45 minutes before a reservation time we're not going to make it, is it important that I call the reservations line to let them know?