Warren Buffett holds USG Common stock

Berkshire Hathaway acquisition of the USG Common stock in 2006 from the SEC :

Date Purchased		Shares Acquired		Price Per Share
08/23/2006		734,700		$45.90
08/24/2006		7,000		$46.03
10/04/2006		371,200		$46.10

November 2009 drywall problems are still there as reported in this video. Blaming Chinese made vs US made, forcing USG competition out?
And new building materials are always on the way, including green ones