Arm-in-arm amidst le tout Hollywood at the post-Oscar Governors Ball this March, billionaire media baron Rupert Murdoch and his wife, Anna, looked on top of the world. As owner of 20th Century Fox, the primary backer of the night's big success story, Titanic, Rupert Murdoch called the headaches of making the movie worth all "the effort and the heartburn." But a month later, Rupert, 67, and Anna, 53, hit their heartburn limit. On April 21, a week shy of the Murdochs' 31st anniversary, a spokesman confirmed that the couple was amicably separating but trying to work out their differences. Immediately, published reports suggested that Anna had finally tired of her husband's workaholic ways.

Acquaintances of the couple's were quick to register shock. "If [Anna Murdoch] was having personal problems, she didn't show it," says L.A.'s Melrose Elementary School principal Regina Goldman, whose students had met the mogul's wife less than a week earlier during a trip to 20th Century Fox's L.A. studio. Says Murdoch biographer William Shawcross: "It's always been an extremely strong marriage." But, he adds, "each of them is a very strong-willed person."

Murdoch was separated from his first wife and running a string of Australian papers in the mid-'60s when intern-reporter Anna Torv came to interview him. Years later, after bearing their three children and writing several successful novels, she alluded to frustrations. "I'm a regular wife who would like her husband not to work so hard," she told the Los Angeles Times in 1985. "But I don't nag, I just sigh."

Shawcross, for one, is optimistic about a reconciliation. "Anna wants Rupert to spend more of whatever years he has left on family and less on work," he says. "This is a kind of ultimatum."