LOVE CATS Webber, Cowell (Photo: Getty Images) With famed composer Andrew Lloyd Webber as mentor, last night's American Idol proved a simple task for nerd Idols with a musical-theater or acting backgrounds. Unfortunately, that left two of the remaining contestants, Jason Castro and Brooke White, with their work cut out, and they clearly struggled. White actually committed an Idol first of flubbing her lines and—gasp!—asking the band to start over. Given the strong performances of the other four contestants, an old-fashioned popularity contest should determine who joins them tonight in the bottom three. If Idol history proves anything, don't expect it to be a cute boy.