Cannot sell the last two seats via the web

Hello All,

We have a strange issue with the last two seats of a performance (education event) when trying to sell them via the web.  The web shows two seats available, but when I attempt to add one or both of these seats to my cart, it is unable to add them to the cart.  In prior cases, we would troubleshoot this issue by opening a ticketing order and see what happens when we try to make the same purchase.  This time, however, we were able to sell the two remaining seats without problem via ticketing.  There are no exceptions generated by the WebAPI.  Does anyone have any idea on why we are unable to sell these last two seats?  Almost all the other seats in the performance were sold via the web without any problems.  We have checked the dates of the MOS etc. and found that everything appears to be setup correctly.  We have some frustrated patrons trying to purchase these seats.  Any assistance will be greatly appreciated.

Thanks,

Allen