
Hi Spizz, just thought I'd add my two pennies worth ;)
I can well understand that you are disillusioned at the moment with your pup and it must seem like this behaviour has been going on forever, and I know this is no excuse in your eyes, but he is
only 6 months old and it
will improve with age and correct training, although it probably doesn't seem like it at the moment.
I have a similar situation to you, my pup is nearly 4 months and as she is a large breed, she already dwarfs most pups her age :P She is very boisterous around my 8 yr old daughter, ripping her clothes and breaking the skin, but I have the advantage that already having an older one of the same breed, my daughter is a little more used to the behaviour and remembers when our older one was young. What I have been doing is monitering pup and child, whenever pup bites like crazy and leaps at her, my daughter gets up and leaves the room, no eye contact, no speaking, Pup obviously quitens down............eventually..... and then my daughter comes back in, makes pup sit and gives her a treat. Under no circumstances does the pup get a treat until she is behaving. I have also been getting child to feed pup at least one meal a day and she always makes pup sit and wait before giving her the command "ok" to eat.
Dog/pups to tend to take advantage of little people as they treat them like litter mates/lower pack members. Little people tend to run around quickly making lots of high pitched noises so it gets the pup excited.
What do you do when your pup leaps at your daughter and bites her? I try to let my daughter take some control before I step in, because it is no good me doing the reprimanding all the time, as the minute my back is turned, the pup will just do it again. They have to learn to get along together.
Hope I've made some sense, it's very hard to advise/get my point across on the internet but giving you my experiences, I hope may help :)
From the sounds of it, you definitely need professional guidance, as the dog can't "know" whats acceptable until you have been advised on how to deal with/train the behaviour. I know you've had dogs before but they all have different needs as I have certainly learnt over the years :D
Good luck, HTH :)