[pooh]

If I may offer an experience, a few years ago friends were up north for the summer, they were snowbirds at the time. They were returning and were now going to be frogs. Their house was unoccupied for months.....all was well with the carpet. Checks over the summer still showed the carpet to be spotless. Then, they were coming back. Into the house we went to make sure all was ready for their return.....the carpet had black spots all over the place...some in the bedrooms, some in the living room. Climate control kept the house at optimal environmental conditions while they were up north, but those spots just came up. Cleaning the carpet didn't resolve the spot situation for any length of time. Luckily, they were tiling the great room and eventually had laminate flooring installed in the bedrooms. It was quite a mystery and we couldn't figure out how spots would suddenly appear on carpeting when no person was in the house and they weren't evident previously. By the way, the carpeting was a light beige, sort of cream color.....just incase that provides some clue. In my house we had a tan color carpet and those types of spots never did show up. Now we have laminate where carpeting once was.