I encountered this as well as few days ago. I was trying to use a DL gift card. Of course, as you mentioned it takes you on a circle to get to your wallet, which DL gift card do not show. Even if you select something from your wallet you have to start all over with the booking. I called and spent over an hour on the phone with two reps and they were in the dark and didn't seem to understand the situation or how or what things are stored in your wallet. They had me log out and go through the booking process (not logged in) and when you click the "Pay with e certs etc..." link, rather than give you another login to your wallet the page that loads lets you enter an e-cert of Gift card. So, basically if you are logged in you cannot use a gift card - period. If you are logged in, you get stick with having to log in again at the end of the booking process and then start it all over - again. The way the payment page use to work was great and easy. The agent said she would write it up. That's the best I could get. My hopes are low as she did not see it as an issue since I was able to ultimately use the gift card by not being logged in.