I disagree. I had new BB7s and they did the same the first time I rode them. Then I removed the pads and saw that they were very dirty. But still, even after cleaning them they made horrible noise and from what I can tell, BB7s are never quiet using the stock pads. I recommend Avid organic pads that come with the BB7 RSL. They are cheap, quiet even in wet conditions and they break very well.
Why would you have to buy new rotors when the pads are contaminated? You can clean the rotors with Acetone e voila.