This happened to me in May -- didn't get a confirmation e-mail, so I thought I must have failed to hit the final confirm or something. Then went in and booked again. Fortunately, it was a restaurant that wasn't difficult to get into -- the Wave. When I showed up, they had both of my reservations, both in my name with the same e-mail, phone #, etc. I felt so bad for having 2 reservations booked, and I explained why I rebooked. The hostess said that sometimes happens, but she didn't know why. The CM seemed much less concerned about my double booking than I was.