The dueling beauties fell to the floor in a two-fisted tussle at Boardwalk bar Duke Macks. A shocked spywitness tells us:

"Words were exchanged when Reid made a disparaging remark (about Starkman) to Margolis. Cindy grabbed Reid's hair and physically yanked her off her bar stool onto the floor," -- a statement not contradicted by Margolis' publicist, Neil Cirucci, who confirmed that a fight had taken place.

"When things happen that concern Guy, Cindy can get pretty nasty sometimes. Otherwise, she's got a pretty good disposition," Cirucci said.

Our snitch added that, besides the hair-pulling, there were a few fists thrown and a kick or two between the combatants before bartender George Ziegler intervened.

The bar manager told us: "Cindy was asked to leave by the back door."

Reid's rep did not return calls.

Ironically, the women were in A.C. for the middleweight bout between Bernard Hopkins and William Joppy, which Hopkins unanimously won. In the bar, chuckles our source: "Onlookers gave a split decision to Margolis."

LETTERMAN SCHVITZER

There's hope for David Letterman in his attempt to get Oprah Winfrey on his show for a "Super Bowl of love."

Letterman's been unhappy ever since reading Richard Zoglin's interview with Winfrey in Time magazine -- in which she says she will never go on his show again after being "the butt of his jokes" during two appearances. Zoglin tells us that Winfrey had been particularly offended by Letterman's jokes about her weight.

But the reporter also reveals that Winfrey gave the late-night host praise that ended up on Time's cutting-room floor.

"I think he is really one of the most brilliant comedian hosts of our time," Winfrey said. "I think he's really brilliant."

CIA, OSWALD & JFK

Norman Mailer, Don DeLillo, Gerald Posner and other JFK assassination buffs are lending their support to a new lawsuit against the CIA.

They want the spy shop to release documents about agent George Joannides, who had contact with Lee Harvey Oswald in 1963. Joannides supervised a C.I.A.-funded anti-Castro student group that Oswald, who supported the Cuban dictator, tried to infiltrate.

The writers allege the CIA has hidden Joannides' intriguing connection to Oswald for 40 years. Mailer, DeLillo, Posner and others published an open letter to the government in the current issue of the New York Review of Books.

Posner told us, "I'm just furious at the government for not releasing every file they have that is tangential to this case. I frankly don't think the files are going to be explosive, but the longer the CIA keeps them, the more it appears it has something to hide. They have to be their own worst enemies."

Not counting the aliens who are secretly reading their minds, of course.

SIMON'S 'DILEMMA'

Since the departure of Mary Tyler Moore, frustrations have continued to fester on the set of Neil Simon's new comedy "Rose's Dilemma," which opened recently.

A spy tells us that John Cullum, who stars in the play, went ballistic during recent rehearsals and publicly berated the playwright as well as the director, Lynne Meadow.

"(Cullum) was at the theater spouting out his complaints," says our source.

MTM walked out on the play Dec. 3, after Simon reportedly wrote his star to say, among other things, "Learn your lines or get out of my play."

Simon, who is struggling with a kidney ailment, has reason to be stressed: The beloved writer of 33 plays, including "The Odd Couple" and "Brighton Beach Memoirs," has had a more than a decade of flops since his 1991 hit, "Lost in Yonkers."

HOT 'CHEERLEADER'

Musicals based on movies have met with varying degrees of success recently: From uber-hits "Hairspray" and "The Producers" to flops like "Urban Cowboy" and "Dance of the Vampires." The buzz on Broadway is that Bill Augustin and Andrew Abrams' "But I'm a Cheerleader" could be the next big show.