Omg that performance of Audience was her best ever O_O
I'm not really sure if that counts as lip-synching though. She did sing it... it was more as a backup vocal or something... she also used it when she performed Fly High at the Japan Gold Disk Awards on the same year, except she let it sing about half the song
http://www.youtube.com/watch?v=GTwBw...i%20fly%20high
She lip-synched one line in HAPPY ENDING @ her AT2005 tour when she was acting "very emotionally", but other than that, it's very hard to tell. Many artist usually lip-synch during ballads to "rest".