Last week I booked two itineraries on the web. For each itinerary, I choose seats. When I looked at one, no seats were shown as selected. I tried to go back and select but the seats on all four legs that I wanted were selected. I called and the agent said that the seats must have been taken by other travelers. I asked about the exact seats on all four legs. She then transferred me to the web folks. The agent there saw two bookings for the identical itinerary. I had also been charged twice. Fortunately, she cancelled it. I called back the next day within the 24 hours and made sure it had been cancelled. I'm not sure if I would have caught the double booking until I got the credit card bill.