What are the disadvantages of buying a home with a subsidized loan?

I am interested in buying a home and there is a program that offers 7500 toward closing costs and down payment for homes in specific subdivisions by specific builders. The loan is forgiveable if I stay in the house for ten years . My credit score is 650. I read somewhere that I might have to recapture tax for some of the benefits of the downpayment istance. What does that mean and what are the other disadvantages?