It sounds like a cheesy Hollywood movie: White college girls from Arkansas go to a national step dancing competition -- a dance form that is a hallmark of black fraternities and sororities -- and, gee whiz, win the whole darned thing! Boy, are the black sorority sisters steamed!

But wait!

In the final reel, five days after the results set off a national ruckus, show organizers say they discovered a "scoring discrepancy." They say the second-place sorority from Indiana University -- Alpha Kappa Alpha, the nation's oldest black sorority -- is also a winner! Each team gets $100,000 in scholarships!

The only problem with this eye-rolling scenario is that . . . it actually happened. And the Feb. 20 national finals of the Sprite Step Off competition in Atlanta, in which the all-white Zeta Tau Alpha team from the University of Arkansas at Fayetteville won what sponsors billed as "the largest Greek stepping competition ever," is scheduled to be broadcast Sunday on MTV2.

"I was nervous it'd be a train wreck and we'd go too fast," Zeta team member Alexandra Kosmitis, a junior accounting major, said of its nine-minute "Matrix"-themed performance. "But halfway through, it became more about having fun."

When the team finished -- to wild applause -- emcee Ryan Cameron, a local radio personality, rushed onstage: "Whoa! Wow!" Then he playfully admonished the sold-out, nearly all black crowd of 4,600, not to be so surprised that the only white contestants were that good.

"Close your mouth! Close your mouth!" he said with a laugh. "Stepping is for everybody. If you can step, you can step."

But when it was announced that the Zetas won, large sections of the crowd starting booing. Internet and radio-call-in warfare broke out when the videos were posted on YouTube. There were allegations of cultural theft and reverse racism, not to mention race-based taunting and name-calling.

Last week, Sprite officials said they discovered the scoring discrepancy. This was odd because the show host, rapper Ludacris, assured the crowd that the judges' scores had been "double-checked."

Footage of the Zetas' routine has drawn more than 500,000 hits on YouTube. Anthony Antoine, a community activist and HIV prevention coordinator in Atlanta, said he shot and posted it "just so my girlfriend could see how good those girls really were."

Instead, viewer comments have been so vitriolic that friends urged him to disable the comments entirely. He declined.

"I watched a grass-roots effort of young people, black and white, play a key role in putting Barack Obama in the White House, and I thought it said so much about the best of this generation of America," Mr. Antoine, 40, said this week.

"And then some white girls win a step competition and it exposes the worst of this generation of America."

Step dancing, a hybrid of military drills, cheerleading and synchronized dance, became popular among young black Americans some 40 years ago. It has since become a staple activity of many black fraternities and sororities which, in their 100-year history, have had to overcome hostile receptions on most U.S. campuses.

"Stepping is one of the cultural things that we recognize as keeping us together, as a people," said Lawrence C. Ross Jr., author of "The Divine Nine: The History of African American Fraternities and Sororities in America."

In August, Sprite and the National Pan-Hellenic Council, the coordinating agency for the nine international black fraternities and sororities, launched the Sprite Step Off, with rounds of qualifying events leading to the national finals in Atlanta. The event's black roots and appeal were clear; in promotions for the contest, every participant is black.

But down in Fayetteville, Ark., the Epsilon chapter of Zeta Tau Alpha had been stepping for some 16 years. Ms. Kosmitis said the chapter had been introduced to the tradition by a black sorority during a "unity night," when white and black Greek organizations swap traditions, in the mid-1990s. Her sorority had competed on campus ever since. When the group saw the Sprite competition, "we thought, well, why not try it?"

The team won two preliminary rounds, earning one of seven sorority spots at the finals.

"I grew up taking dance lessons my whole life, and most of the girls in the group had dance or cheerleading experience," Ms. Kosmitis said.

Meanwhile, Jasmine Starks, a junior majoring in African and African American diaspora studies at Indiana University in Bloomington, who says it was her first time to step, put together a step team that also made it to the finals.

The AKAs' routine was based on the "Law & Order" television show. "We agreed to go out there and leave it on the stage," Ms. Starks said. "When I came offstage, I actually threw up. That's how much effort we put into it."

Mr. Antoine, who shot the video, and Mr. Ross, the author, who watched both routines on video, each thought it was close but that the Zetas won.

"If you take race out of it, it doesn't matter if the Zetas won," Mr. Ross said. "They were good. They won. It's reasonable to believe the AKA routine was better, but it's debatable. That's it. The only reason people are upset about the winners is because they were white."

Melody McDowell, chief information officer for the national AKA office, was there. She thought the AKAs had clearly won.

"I was shocked," she said.

Radio call-in shows and Internet message boards lit up, many with angry black callers and posters. The judges -- R&B diva Monica, producer Devyne Stephens, Rozonda "Chilli" Thomas of TLC fame, and dancer-choreographer Zack Lee -- were getting hammered so hard on one Atlanta call-in show that Ms. Thomas called in to defend herself.

"The AKAs from Indiana, hands-down in my opinion, should have won," she said. None of the judges returned calls for comment.

Spokesmen from the Coca-Cola Co., Sprite's corporate parent, offered only a vague official statement: "We conducted a post-competition review and discovered a scoring discrepancy. There is no conclusive interpretation, nor definitive resolution for the discrepancy." Thus, Coca-Cola gave both groups $100,000. (The second-place prize had been $50,000.)

Warren Lee, chairman of the council of presidents of the National Pan-Hellenic Council, said: "We were not so much unhappy as we were confused. We were not sure if the rules had been applied as we understood them. So there was some review, and it's my understanding that one person made an honest mistake in the scoring."

Mr. Antoine said he left the show that night exuberant about so much positive energy -- but, somehow, the video he posted has drawn nearly 3,000 comments, "85 percent of them negative."

"I would really like to think there actually was a scoring problem, but I just don't think so," he said. "I think there was such a backlash that Sprite looked for a way out of it. They put on a great event. I'm sure they didn't want people mad at them. I would just have to conclude that we have a lot of work to do, racially speaking. I'm glad that video is out there, so that people can see that."

Washington correspondent Daniel Malloy writes the "Pittsburgh On The Potomac" blog exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.