Hi Ron,
I managed to review and reserve my seat 24hrs before my flight. However, I found that the system didn't accept my e-ticket number but did accept my Airline Reference number (which is a 6 figure code consisting of numbers and letters). There is a drop down menu box that allows you to check your reservation against either your Frequent Flyer number, your e-ticket number or your Airline Reference number.I also found that I had to re-click on the submit button a couple of times as on the first couple of occasions the page came back as unavailable. Guess ther's a glitch on the system.
The only other option would be to phone reservations and pre-book your seat.
Hope this helps. I'm off on tonight's flight to AUH and will soon see if the system works!