Supply and Demand
Due to the relatively high costs of producing digital imaging sensors, only a few companies in the world do it. One of the largest is Sony. Sony makes CCD chips for almost every digital camera company in the market.
So when a production run of sensors is faulty, the effects ripple far and wide. Case in point, review this web page: Imaging-Resource.com - NEWS! - CCD failures: the bigger picture.
Sony announced a problem with a particular run of CCDs that, at last count, ended up in 58 different digital cameras from 7 different camera companies. All of the companies are fixing the problem free of charge and Sony is picking up the tab for the whole thing.
So, if your camera is on the list and has been exhibiting problems with image capture, you might be due a free fix.
edit/update: more details about the problem here: http://techon.nikkeibp.co.jp/english/NEWS_EN/20051005/109314/