Dec. 10, 2006  -- It's supposed to say sweet things to little girls like, "You're a wonderful friend," but push its button the wrong way and the Little Mermaid Shimmering Lights Ariel doll may say something else -- "You're a slut," according to a California mother whose allegation came to light in a newspaper report.

The doll's manufacturer, Mattel, doesn't believe it's possible, and a company spokeswoman said the complaint by Stephanie Herrera of San Jose, Calif. -- first reported in the San Jose Mercury News -- is the only one it's heard of.

Normally, the doll says the phrases, "Your sparkles are so beautiful," "Life is the bubbles" and "You're a wonderful friend." It also hums a song without words.

Herrera said she discovered the fluke when her 3-year-old daughter, Juliana, was pressing the button quickly so she could skip the phrases and get to the melody. Instead of just moving to the song, Herrera said her daughter got the wrong message.

"I was in absolute shock," said Herrera, "especially after my daughter repeated it."

Mattel has asked Herrera to return the doll, and the company has offered her a voucher for a toy of equal value.

"We don't believe that any of the product out on the market is affected," said Mattel spokeswoman Sara Rosales.

"A lot of times this is something that's very adult directed," Rosales told ABC News. "A child would never hear this, that's not a part of their vocabulary."

Rosales said she checked another Shimmering Lights Ariel doll and didn't hear anything unusual. She said it was double-checked by engineers and designers who don't believe such a snafu is possible.

Mattel currently has no plans to recall the toy, since the company has only received one complaint.

Ariel is a character from the Disney-produced film, "The Little Mermaid," and Mattel has a licensing deal with Disney to produce the doll. Disney is the parent company of ABC News.

Stephanie Oppenheim, who publishes the independent toy guide Oppenheim Toy Portfolio, told the Mercury News that she put Arial to the test. After pushing the buttons on another Shimmering Lights Ariel doll, she said she heard the naughty word but had to listen really closely to get an earful.

Oppenheim said it could actually be good for business.

"Sometimes, this type of controversy makes a toy all the more desirable," Oppenheim told the Mercury News. "The more quirky toys tend to be more attractive to adult collectors."

She advised parents to test the "try me" buttons on toys before making a purchase.

ABC News bought an Ariel doll, and after pressing the doll's button several times quickly, some employees thought they heard the doll say, "You're a slut" -- but only after listening very carefully. They warned that they could have heard it based on the power of suggestion.

Others said they could hardly understand what the doll was saying when it was sped up, let alone hear the phrase.

Since the alleged mouthy mishap, Shimmering Lights Ariel is not a welcome playmate in the Herrera house. Herrera has taken the beloved doll away from her daughter and given her a different Arial doll to play with.

Herrera said she bought similar Ariel dolls to sell on eBay, but scrapped her plans after the incident.