check this link
http://forums.us.dell.com/supportforums/board/message?board.id=latit_video&message.id=20963&c=us&l=en&cs=&s=gen
http://forums.us.dell.com/supportforums/board/message?board.id=latit_video&message.id=20963&c=us&l=en&cs=&s=gen