It was very clear to me that Ms. Simpson was totally lip synching when she performed her first song. When she was ready to do her second song, she got busted. Period. Someone cued the wrong track. She walked off like a baby because she was embarassed, as she should be. Then at the very end of the show, she tried to blame the whole thing on her band.
(I happen to have the whole thing on tape...I wanted to record this week because of Jude Law )