Checking seats for an already checked in itinerary: was in F (AU). Seat map for a 737-500 showed rows 1-2 full (with my seat appropriately marked)... and gave me the opportunity to select seats in rows 3-6! (I didn't.). Flight was the 6:40 5/29 bos-ewr. I can only imagine what would have happened had I picked 3a on a 735!

Shortly after this, I changed to an earlier flight (and got the y-up). Checking in (not already checked in) I saw the correct seat map for a 735.