Used two of my RUC's for DG wife and PM me for SJU to ATL and ATL to LIT yesterday. Both legs of both reservations notated Systemwide Upgrade when the certs were applied. At check in time it allowed wife to check in and told me check in not allowed and to check in at airport. At airport we immediately go 1 and 2 on UG list to ATL. But I go 1 on ATL to LIT while she is 5. He checked the people between us, and all were regular UG's that the RUC should trump. Agent called Atlanta twice trying to fix without success. I call PM line while on plane before leaving SJU, and she says only gate agent in ATL can do anything once checked in. Irony is that the only way to know there is a problem is to guess what.....check in. Too close on connection to talk to GA in ATL, so we just punted and took the one UG seat and called it a day. Bottom line appears to be that these things are a wild card.