Checking availability on UA 1140 RSW-CLE Dec 5 -- KVS shows Y4, but united.com shows Y9. Why the discrepancy?

Also, when I use airport code RSW in the Fares tab with the Sabre method, I get a datasource error "minimum advance booking of 48 hours required". This has been broken for a while now. If I switch to the Galileo method, it works.