My 04 coupe seems to be locking itself. heres how it goes down...I unlock it with the fob, open a door, shut door, and come back minutes later to discover its locked up on its own. Second time I unlocked it, started her up and shut it down, closed door and came back to find its locked AGAIN

I understand it will relock in 40 sec if no doors are opened and I recall in the past that when I pressed the fob to unlock it would stay unlocked
Any suggestions? Only thing Ive done recently was add led map lights