All the computer knows is that other people who hit the button a millisecond before you have a choice of tickets up on their screen, and the system holds those tickets for those people for 2 minutes. If those people decide to hit "search again" to look for better seats, or if they don't get all their payment info entered in time, the computer will re-release those tickets.
Wow...GREAT ADVICE! That never even occurred to me. DH and I kept searching for tickets in vain, assuming that it was a lost cause, and I think we kept it up for about 10 or 15 minutes, but if I had read this post yesterday morning, I would have kept searching for another 20 minutes. Thanks for the advice...I'll be sure to abide by it next time.