I tried making an SMF/IND trip commencing on 4/9 on united.com. The cheapest fare it could give me was ~$700, but before I booked it the page refreshed and the cheapest fare became ~$900. (Spring break??) I went to travelocity and it almost booked a ticket for ~$600, but after the final click I was told that they couldn't ticket it and my credit card wouldn't be charged. Druing the process I was prompted for seat selection and the seat map for an ORD/LAX leg only showed rows 1 and 2. I figured this was some browser problem and ignored it. After the transaction failed I went to Orbitz and booked a $574 fare. When I looked up the PNR on united.com it showed all flights confirmed with an SFO/ORD leg in first class. (It also gave me only 33 minutes to make the connection in SFO, I hope there's no fog).

My question is what is booking class A and how come united.com doesn't seem to offer it?