Do you know how your travel agent booked it? Did they book directly with PAL?
Rulebof thumb is if you book with OTA, you won't be able to manage online...
Yes, that was my impression as well. However, I am not sure as to how the OTA booked my flights. I was just resigned to the fact that I wouldn't be able to manage it online.
Not that it mattered, though, all aisle seats appeared to have been blocked when I logged on.