Something strange I noticed a few days ago too... For each of my reservations booked through a TA (corporate travel or OTA), under the "Redeem Awards to Upgrade" tab there is the option to upgrade using miles or a cert, but on the "Purchase Upgrade" tab, the selection is greyed out and marked "Not Available". For my one reservation booked directly through UA, both options are still available. I had always been able to buy-up to first via this upgrade tab on the website- even for TA-issued tickets. Wonder if this has gone away?