I pointed this problem out a few days ago on the CO.com Master Thread. I think it's simply a glitch, or an oversight on the programmers' part, that occurred during the latest round of Web site upgrades. Like Rebigulator, I usually pick flights (whenever possible, but fortunately I have a flexible schedule) based on exit-row availability, specifically 14A or 14F on most of the 733s and 735s I usually land on, and having access to advance exit-row bookings is to me the most important element of being a PLT. I booked a ticket a few days ago, and it was frankly a pain in the a** to have to start the actual booking process to see what exit row seats were available.