EVERYONE loves a Hollywood marriage, and even more a Hollywood marital bust-up.

Meet America's sweethearts, hot Hollywood couple Eddie Thomas (John Cusack) and Gwen Harrison (Catherine Zeta Jones, celebrity marriage material herself, of course).

They have broken up since making their latest star vehicle, Time Over Time, but with a movie promotional junket to survive they must fake a re-kindling of the fires to boost its box-office chances.

Can harassed studio publicist Lee Phillips (Billy Crystal) keep the show on the road, while undermining their every move behind their back for maximum publicity? Can prima donna Gwen's dogsbody sister, sensible and newly-slimmed Kiki (Julia Roberts) continue carrying out her personal assistant duties while wishing to declare her love for Eddie? Will the loose-cannon director (Christopher Walken) hand over the finished film in time for the press screening (and will any decent lines ever turn up for Walken's auteur turn?).

By way of contrast with Robert Altman's The Players or the Coen Brothers' Barton Fink, this satire on the Hollywood studio system is too much an insider job, co-written and co-produced by Billy Crystal, and after its snappy start it sags under the weight of navel gazing. (Who, aside from film journalists, understands the machinations of a junket?)

Crystal, reprising his suffering psychiatrist schtick from Analyze This, gives himself far too many of the few good gags, and Zeta Jones's catty queen bitch Gwen has no chance against Roberts, who you forgive for being too witty, striking and sexy for the dowdy role (although she is by far the superior actress in the first place, even slumming it convincingly in a fat suit for a few flashbacks). Cusack, meanwhile, gets the job done but with decreasing enthusiasm, sweating for his laughs whereas Stanley Tucci's despairing studio head milks his few moments to the max.

The satire in Joe Roth's clumsy, predictable romantic sitcom should be more malicious, sharper and stripped of soft-centred Crystal clichs that blighted the City Slickers movies. What was needed was America's sour hearts not Sweethearts.