Roger Federer showed some rare frustration Friday, requesting a change of line judges before going on to beat Belgium's Kristof Vliegen 7-6 (1), 6-4, 6-2 to give Switzerland a 2-0 lead in a Davis Cup World Group playoff. Upset by a baseline call that led to him lose serve and trail 2-0 in the second set, Federer walked to his chair and called for match referee Norbert Peick to change the line... More...