Because those ahead of you in line are taking longer to complete their DVC business than anticipated. All it takes is a systems glitch to slow CM's computers or a something like a first day for booking a special members event to back things up. On a normal day, your estimated wait at 9 AM is probably 38 minutes based on the typical nature of "normal day" calls. But on a day when the calls take longer to address, the wait time goes up.