If you can, find out what company the previous owner used for termite treatment. When we bought our house in October, the termite company that the previous owners used (Superior) told us the contract on our house was paid through February 2010. They transferred remaining coverage to us.
If the previous owners did know of an infestation, they would have been legally obliged to disclose it to you prior to closing. If you find out what company was treating the house, I would ask the company about any prior infestation.
I wish you the best of luck in dealing with this. Hope the rest of your experiences at TV are all good.