You may not think about cleaning the roof of your home but insurance companies now say you should. Whether you do or not could affect your policy. Is your roof dirty? Does it have dark streaks or green moss growing on it? It's not just a nuisance. Insurance companies, believe it or not, are now canceling policies because of roofs they consider too dirty. Bob Foppe never thought much about the dark streaks on his roof. After all, it wasn't leaking. But then he received a letter from his insurance company threatening cancelation. "Yeah, I got a letter from my insurance company. They came a day i wasn't home, took some pictures," said Foppe. The letter indicated mold and algae staining on his roof and on the vinyl siding on the shady side of his house. "They said if I didn't correct it they could terminate my policy ," said Foppe. Mike Jackson runs a siding and roof cleaning business that's getting a lot of business these days...