i just think dogs are fallible (like humans actually) and that anyone who assumes a dog isn't is plain negligent.
Who said dogs aren't fallible?
All I'm saying is that they CAN recognize a threat from a non-threat.
It does take exposing the dog to all different types of people in all different types of situations, so that they can learn to discriminate. This is best done as young as possible, basically from birth on up.
Now, when a dog is on his own property and a stranger with a strange dog walk by the fence, he's going to bark. That's just territorial behavior, but it's also self-rewarding because every time he charges and barks at the fence, the "intruder" keeps on walking and leaves the area. In the dog's mind, he succeeded in chasing off the "intruder", and so is made to feel stronger.
It's exactly the same scenario as the mailman. Every day, the mailman walks up to the property, the dog barks, and the mailman leaves. The dog thinks it was his barking that scared the man away.
Basically, this same scenario is enacted when a pup is started in personal protection training. The pup's confidence is built when he thinks that his barking caused a potential threat to retreat.
Dogs that are fearful, undersocialized, or lacking in confidence may learn to use aggression as a "crutch" when they feel threatened. After all, it's always made those nasty "intruders" go away, so any time he is afraid or uncertain, aggression is likely to become his default response. This is a dangerous situation that can put you in a position of liabiity.
Even stable, well-adjusted dogs will bark at the fence, but should be able to be called off easily, introduced to the person, and thereby assured that there is no real threat. If the dog is unstable, fearful, or simply undersocialized or undertrained, he may not take your word for it that the person is harmless.
If it is your cur dog that is doing the charging and barking at the fence, it is understandable, as curs are notoriously distrustful of strangers. I believe this trait is valued by breed fanciers, as a good hunting dog is a valuable animal. While hounds are friendly and trusting and would allow themselves to be stolen, curs are not, and would no sooner go quietly with a stranger than let their leg be cut off.
While this may be a bonus for rural folk, this is not a temperament that lends itself well to city or suburban life where people are living packed closely together. It sounds like your neighbor may be a transplant from the city. Have you met or spoken to her? It might be worth your while just to let her know that you're concerned about her pup and don't want her to be frightened, and that you're taking measures to keep your dog from charging the fence. It's always a good idea to keep neighbor relations on a peaceful, even keel whenever possible.