It's gonna take time, man. The wife got a "mutt" from the local Angels for Animals about 1 1/2 years ago. The poor guy had been SEVERLY abused by the previous owners....and it showed. He weighed about 25 lbs when he should have weighed 60-70 and was VERY skittish and terrified of everything. He was especially terrified of me. Just me. Every other male that came to our house he'd at least walk over to and check out. With me, he just ran. He spent the first 2-3 weeks on a completely different floor of our house when I was home. If I was downstairs, he went upstairs and vice versa. All I can figure is that I either look or sound like the piece of shit that abused him.
He's getting a LOT better now. He'll come over to me for attention if the wife is in the vicinity but will, usually, still take off if I'm by myself, although he now walks away instead of running like the Devil himself was after him. When I'm not around, he acts like any other dog, playing with the 4yo daughter and all, with the exception that he follows the wife around like he's glued to her most of the time. Must be something with being abused, I read that quite a few times above. Give it time, the poor thing will come around. It'll just take some time and love.
Bub