Originally Posted by
InkUnderNails
I actually prefer different confirmation numbers. My first one gets me to my destination city and is promptly forgotten, filed away in reimbursement purgatory. The next flight is a new itinerary and a new number, infinitely changeable and flexible without thought of the outbound.
There's also the reported problem that you can can't check in for your return until after the outbound. For a 1-day trip that guarantees you a bad boarding number for the return flight.