I live in New England, and our house was built in July through December of 1999. It is a two level straight front colonial. I have noticed many cracks in our drywall. Most are in corners. There are a handful that are not. They all go in a straight line, none are crooked patterns. We have forced hot air, and my builder said that it causes more drying, and they see more cracking. I am just not sure if this is serious, or more of a big problem. The builder sent the painters over to fix it some of them. I was painting in my 1/2 bath on the first floor, and noticed a 5 inch of so crack over the door jamb...there is also a horizontal crack above this where the wall meets the ceiling. This is what prompted my message.