We just recently mandated the use of Concur Travel at our company.  In the last several months, travelers seem to be experiencing issues selecting airline seat when they are booking.  We have seen two issues:

1.  The traveler selects seats, receives an email indicating that they are confirmed, and then later discover that they don't have seats when checking in for the flight.  No notification to indicate that seats were not selected.

2.  The traveler selects the seats during the booking process and then once the booking is finalized, the seats are arbitrarily changed without notice.

Has anyone seen similar issues and what do you recommend to travelers?