Puppy/Adolescent snorting, growling

I have a seven month old rescued 'pit bull type' mix, possibly with some sort of wirey haired terrier. Anyway, this dog has inherited neurological problems, for which she is under treatment for with prozac. Her mother was intensely shy and a fear-biter according to the shelter, and most of her pups have inherited this problem. NILIF training has handled most but not all of her fear, and the prozac seems to help pretty well with the rest. She is for a 7 month old I think very well trained, except for this one problem. Since bringing her home 4 months ago, she has always growled and barked rather savagely and run from my boyfriend when he comes home, but only when he is coming up the stairs. Once he's up the stairs she runs around snorting and snorting and snorting, and after 5 minutes or so is fine and happy to see him and wants treats and petting and waits patiently at his feet til she gets it. Once she's relaxed her body language is soft and friendly, with no signs of even anxiety. He ignores her when she misbehaves, doesn't chase her when she's running, but after months of this he is beginning to get very tired of it ... and so am I. He's the ONLY person she'll bark and growl and show teeth to, and he's never laid a hand on her that she didn't come for (after she's settled she wants attention and petting). Trying to condition it out with rewards and training has done nothing, either with ourselves or two professional trainers. We're on the third trainer now, who has recommended a shock/vibration collar and I am concerned this will make her mean. I am also afraid this behavior will escalate into biting one day, and there's obvious danger there. Can anyone provide advice/alternate training methods, or what additional information I need to provide?

Puppy/Adolescent snorting, growling