Wired.com: DELL recall 4 million batteries

What 's wrong with DELL this year, its laptops sold with slowly speed, and the company provide a lot of promotion. This reduce the income of this largest computer supply 50% last year. What happen? The reason is the DELL laptop can be burned into flames caused by its battery cell made by Sony. Now Dell is recalling for notebook batteries from between April 1 , 2004 and July 18 this year, and customers will have free replaced batteries from DELL.
TO illustrate, Dell officer confirmed that his laptop caught fire in Illinois , later in Japan and Singapore. And as I think , a machine obsolutely can not work too much for a long time, it got fire is not a strange event. Just wonder why the company make it so big problem.