I haven't seen his show, but I am currently working with trainer who uses a lot of his methods. Basically establishing that YOU are the alpha dog, and yu decided what happens, when and where. Like in nature, you have to tune in to a dog's pack-mentality, and you have to be the leader of the pack. It's great, I can't believe the positive changes and imrovement in behavior - and a lot of it is training ME how to speak to my dog in a language that he can understand - he does not understand when I get mad and yell or if I get so frustrated that I don't know what to do with him. Basically, my dog was ruling me and telling me how we would do things - not repecting my authority.
But, one of the fundamentals of his training is to give what he calls the 3 things your dog has to have to survive: Excerice, disapline and affection, in that order. So, with a little one taking up a lot of time, your pup is probably feeling the lack of at least one of these things. The Cesar Milan site is so-so, you pretty much have to buy his stuff to get anything out of it, but it might be a good read, or seek a trainer in your area who uses his methods. There are some who come into your home for problem dogs- I know of a similar problem with a woman who worked in my office. She had a small dog who was heavily misbehaving when the new baby came home - it turns out she saw the baby as a threat, and they needed to work past it.