Is Ashlee's career in pieces?

Not everything on SNL is live, the pop singer proves in a botched lip-synch Saturday night. The fallout, if any, is unclear.

NEW YORK - If Ashlee Simpson's stomach was upset Saturday night, imagine how she's feeling now.

The 19-year-old singer was busted for a Saturday Night Live lip-synch gone awry. Her manager-father said Monday his daughter used the extra help because acid reflux disease had made her voice hoarse.

"Just like any artist in America, she has a backing track that she pushes so you don't have to hear her croak through a song on national television," Joe Simpson told Ryan Seacrest on Los Angeles radio station KIIS-FM. "No one wants to hear that."

He insisted it would be Ashlee's live voice alone during her appearance on NBC's Radio Music Awards Monday night.

And he said she has never used the extra help onstage before.

Simpson had performed her hit single Pieces of Me without incident earlier on SNL . When she came back a second time, her band started playing and the first lines of her singing Pieces of Me could be heard again.

She was holding her microphone at her waist at the time. Simpson looked momentarily confused as the band plowed ahead with the song and the vocal was quickly silenced.

A flustered Simpson made some exaggerated hopping dance moves, then walked off the stage.

Although she had blamed her band on the air, MTV.com reported that Simpson on Sunday took full responsibility, saying her voice was ragged from too much work.

"I can't cancel something like SNL, " she wrote on her Web site. "You and I know that even if I synched on it or not, I'd still get seen by millions, maybe even make a few more fans. I'll hold my head high and say I think it was silly of me to do it, silly of me to blame the band. ... But I don't think it did me much harm, and people will see that soon."

The incident exposed what many consider an obvious secret: that some singers who appear onstage aren't singing live at all, or at least have their voices augmented by backing tracks. And it's happened before on Saturday Night Live, too, executive producer Lorne Michaels told the Associated Press.

"She was mortified and in her dressing room, but (producer) Marci (Klein) got her to come out for goodnights and explained that it wasn't the end of the world. It wasn't her fault," Michaels told AP Radio.

"Every artist that I now in this business has had vocal problems at some time - from Celine on down," said Joe Simpson, who is also the father of Jessica Simpson. "So you've got to do what you've got to do."

He said it was his decision to use the tapes when it became apparent that acid reflux disease had swollen Ashlee's vocal cords. After consulting Wayne Newton's doctor, she received a cortisone shot to get her ready for the Radio Music Awards , he said.

It was the band's drummer who pushed the wrong button onstage, he said.

Simpson was the talk of the Internet after the appearance.

"Go away, Ashlee," one post on her Web site said. "If you wanna be famous for something, choose something you can actually do. Maybe you could get naked for Playboy. "

Other fans leapt to her defense.

"Mistakes happen," said another posting. "You're probably all just jealous because you sit at home and wish you were a celebrity and then as soon as one has a mishap, you're right there to rub it in."

Entertainment headlines