Two young contortionists wash away their innocence in the "Waterbowl" segment of Cirque du Soleil's naughty "Zumanity."

People always ask, "Why so many Cirque du Soleils? Why are they so successful in Las Vegas?"

Here's one answer: Failure is not an option.

Unlike much of the competition, Cirque has deep pockets, a patient corporate partner in MGM Mirage and custom-built theaters that discourage drastic moves. After the company gutted the general-use theater at New York-New York to install the decadently curvaceous Zumanity Theatre, I would always tell people, "There will be a show called 'Zumanity' at New York-New York, and it will be a hit, even if they have a trained seal act onstage."

It never came to that. But a recent party to mark the start of the revue's third year also showed off the continued tinkering with a title that once threatened to snap Cirque's winning streak.

The naughty cabaret show was a bold attempt to find a new direction, but it got off to a rocky start. Cirque launched it in August 2003 with a big party, but then said the show wasn't quite ready. They launched it again a month later with an even bigger party, then said the show would be ready by Christmas.

Two years later, it's about ready.

The creators have kept the strong acrobatic set pieces and even added a new one -- a sexy aerialist (Julia Kolosova) doing fun things with hoops -- but also worked to strengthen the connective material and give it more of a flow.

The biggest change was to get rid of the lame comic relief, a quartet called Spy Monkey that dressed up as Puritans to protest the "debauchery." The new comedy comes from Nicky Dewhurst, an old pro at these things who transferred over from "Mystere," and new female comedian Shannan Calcutt.

Their pre-show antics illustrate the difference between the old and new "Zumanity": Before, it would have been deemed funny enough to wave dildos in the face of patrons. Now, the antics actually lead to a visual punch line. Calcutt later breaks the Cirque tradition of little-to-no talking for a funny instructional on how to make cheap breast implants. She drops her top to blend right into a "Zumanity" subtext of embracing all body types, not just the gym-and-implant bods usually flaunted on the Strip.

Artistic director Ria Martens puts more zest into the choreography and gives new purpose to some notorious moments -- such as a male kiss -- without changing the show's basic premise, including an opening parade to introduce the cast as exotic individuals.

And while the show always featured two singers (Corinne Zarzour and Lonnie Gordon) and original songs, they seem more integrated into the action now. "Zumanity" still missed a ripe opportunity to have its songs really amount to something -- maybe even get its Cirque admirers from the pop and rock world to write some -- but it's an improvement.

Host-in-drag Joey Arias leads us through the slightly rearranged running order with shorter, snappier patter. The strong acrobatics still stand out as daring combinations of eroticism and athleticism: Contortionists Ulziibayar Chimed and Ariuna Batchuluun exploring young love in a giant "waterbowl," and aerialist Robyn Houpt flirting with sadomasochism while entwined in black straps, her heavy breathing amplified and underscored by elegiac music.

A third act is equally strong, but on this night showed how the individuality of the casting can be a double-edged sword. The aerial ballet using long strands of fabric lost much of its poignancy when Alan Jones Silva, the little man who usually pines for airborne goddess Olga Vershinina, was out with an injury. Ebon Grayman took over the role in his character of a Satyr, but it just wasn't the same.

"Zumanity" still shouldn't be left alone. A cheerleader gag held over from the Spy Monkey days wouldn't be missed. And there's a trick on an audience member involving knives that's a lot funnier when Penn & Teller do it. And speaking of audience recruits, there's another fake-out at the end that leaves the audience feeling a bit conned, and wondering if other "volunteers" throughout the evening weren't planted as well.

But the show is moving the right direction. And that's a good thing, since it's going to be here a long time either way.