I've got the same model as you, and I had this exact same problem. It turned out to be that one of my door-locks wasn't fully engaging (although it did actually prevent the door from being opened), and so the central locking controller didn't think the car was locked, meaning that the confirmation indicator-flash didn't occur. The door lock in question (the front-passenger door in my case) was replaced and it sorted out the problem. Don't know how much this cost though, I'm afraid, because it was done as a warranty claim. Hope this helps
