Its quite common in newly built homes to see the coax tacked or stapled to the studs of the walls.
I personally think they do that so that you CAN'T use it as a pullstring for new cables and is a way of making you rely upon the builder for your cable runs. We all know that its not that expensive to run a new line of coax around your home but these guys will charge around 75 bucks for each additional coax jack you have them run for you. Typically in moderatley priced new homes they only give you 2 coax jacks regardless of the size of the home.
I had my home built in April of '04 and it has 3 bedrooms, and a living room, and I was only given two coax and two phone jacks. If I wanted more then I'd have to pay for each one. I feel that is the where Shawn is at in his situation.
Shawn is there any crawl space or were you built on a slab?
Are you in a town home??
You may have mentioned earlier, but is your home more then 1 story??
FYI:
a prefab or manufactured home refer to "trailer style" homes.