Molly has the same problem. Our guess is that she wasn't being well taken care by her breeder by the time she came to us; she was five months old than, so there's no telling what went on during that time. She's improved tremendously from where she was some two years ago. How long have you had Sesh? It'll take time...but I'm sure he'll improve if you try to socialize him a bit. Do you have a Dog Park in your area? Those are great places for socialization. What about Obedience Classes? I've heard those help a great deal to boost the dog's confidence. Is he just like this with your neighboor, or with people he doesn't know in general?