Trouble with ReserveTicketsSpecifiedSeats and Seats Donated for Resale

Hi, all!  I am having an issue where we have seats donated for resale in our Test system, but the ReserveTicketsSpecifiedSeats API call refuses to let me purchase them, giving the following error:

Tessitura.WebAPI.TessituraSeatServerErrorException: TESSITURA_SEATSERVER_EXCEPTION:Error 50000: {One or more of the selected seats is not available}

   at Tessitura.WebAPI.SeatServer.SeatServerConnectionImp.ReceiveResponse(String sessionKey, UInt32 requestId, StatelessCommand command, MessageHeader& header, Byte[]& messageData)

   at Tessitura.WebAPI.SeatServer.SeatServerConnectionImp.ExecuteSqlInternal(String sessionKey, Boolean forceEstablish, String command, SeatServerPool pool, Boolean preBroadcast)

   at Tessitura.WebAPI.SeatServer.SeatServerConnectionImp.ExecuteSql(String sessionKey, String command, SeatServerPool pool, Boolean preBroadcast)

   at Tessitura.WebAPI.SeatServer.SeatServerConnection.ExecuteSql(String sessionKey, String command, SeatServerPool pool, Boolean preBroadcast)

   at Tessitura.WebAPI.SeatServerTicketer.FindSeats(SeatRequest oSeatRequest)

   at Tessitura.WebAPI.Tessitura.FindSeats(SeatRequest oSeatRequest)

   at Tessitura.WebAPI.Tessitura.ProcessSeatRequest(SeatRequest seatRequest)

   at Tessitura.WebAPI.Tessitura.ReserveTicketsDirect(String sWebSessionID, String sPriceType, Int32 iPerformanceNumber, Int32 iNumberOfSeats, Int32 iZone, String sSpecialRequests, String RequestedSeats)

   at Tessitura.WebAPI.Tessitura.ReserveTicketsSpecifiedSeats(String sWebSessionID, String sPriceType, Int32 iPerformanceNumber, Int32 iNumberOfSeats, Int32 iZone, String sSpecialRequests, String RequestedSeats)

Any ideas on what I may be missing here?

Thanks in advance!