We went in July, I pre-ordered tickets at the urging of the CM who I talked to about the show...
While we were in line to pick up our tickets at the Window, this man and his wife (who said that they had pre-ordered tickets) were told that their tickets weren't available, their order had been cancelled... He tried to get tickets for that same night (this was the second showing, 9:30, I believe) and was told that there was a sold out show that night, but he could get tickets for a show 2 days away.
Just a word of caution, order early (you'll get great seats!), and be there to pick them up early as well. The lines can get ridiculously long...