Set over one weekend at a Las Vegas desert-set press junket, big-screen actors and married couple Eddie Thomas (John Cusack) and Gwen Harrison (Catherine Zeta-Jones) have come to promote their eighth picture together, entitled "Time Over Time." With Gwen's last two Eddie-less films bombing in the states, a lot is riding on the success of "Time Over Time" to boost both of their careers. Only one problem stands in the way of a peaceful weekend of joint promotion; Eddie and Gwen have split up and are currently not even speaking to each other.

Enter Lee (Billy Crystal), a studio publicist who has been hired to reconcile Eddie and Gwen's relationship, or, at the very least, make it seem to the press that they are still getting along. This task won't be an easy one; Eddie is in a state of depression, and still believes he is in love, while Gwen has taken up with a Spanish lothario named Hector (Hank Azaria). Further complicating matters, Gwen's sister and personal assistant, Kiki (Julia Roberts), has secret longings of her own for Eddie.

If "America's Sweethearts" wants to take a ruthless, sharp jab at the Hollywood industry, it is far too soft around the edges and lacks the wit needed to accomplish such a task. If it wants to make a statement about famous marriages and the press surrounding celebrities, the same idea was put to far better use, and was infinitely more telling, in 1999's "Notting Hill," also starring Roberts. If it wants to be a screwball comedy in the tradition of Preston Sturges, it hasn't the energy to even get off the ground running. And, finally, if it wants to be a romance between Eddie and Kiki, I've seen more sparks fly between ostriches.

Watching "America's Sweethearts" is a disheartening experience. It starts off slowly, has a middle that creeps along at the speed of an asthmatic octogenarian, and finishes up with a conclusion that is neither gratifying nor inspiring. While a few winning moments sneak in throughout (Roberts' distressed Kiki, formerly sixty pounds heavier, falls off the wagon and digs into a breakfast big enough for the entire salvation army), they are only fleeting glimpses of what might have been had the screenplay gone through some major rewrites. Not helping matters are a collection of characters (excluding the mousy Kiki) who are self-involved, uninteresting, and not nice. Who wants to watch a film--one that attempts to be a romantic comedy, no less--when you can't even stand to be around the participants?

Julia Roberts (2000's Oscar winner for "Erin Brockovich") isn't the world's most popular actress for nothing. She injects life into the slimmest of parts, and "America's Sweethearts" offers her her most thankless role since 1991's "Hook." While Roberts' Kiki is the sole likable presence, as she gradually learns to stand up for herself, she is underwritten and not terribly engaging. Almost every scene that does work includes Roberts, however, whether she be stuffing her face with breakfast, blowing up at the vacant idiocy of Gwen and Eddie, or sharing a tender moment with Eddie in a flashback that finds her equipped with a pudgy face and a fat suit (read: a normal, American body).

John Cusack (2000's "High Fidelity") and Catherine Zeta-Jones (2000's "Traffic"),as title couple Eddie Thomas and Gwen Harrison, are far above their roles. Cusack, good in just about everything, must resort to jokes about falling on the spines of a cactus to get laughs. Zeta-Jones plays the pampered actress to a hilt, but the sheer phoniness of her character does nothing in the way of making her an attractive presence. Billy Crystal (1999's "Analyze This"), as the determined, smarmy Lee, has one good gag involving a Doberman attracted to his crotch, but might as well not have even been present for the rest of the picture. In minor roles, Christopher Walken (2001's "Joe Dirt"), as the maniacal director of "Time Over Time;" Hank Azaria (1999's "Cradle Will Rock"), as Gwen's flamboyant new flame; Stanley Tucci (2000's "Joe Gould's Secret"), as the head of the production studio; and Seth Green (2001's "Josie and the Pussycats"), as Lee's eager, but clueless, assistant, have little to do.

"America's Sweethearts" squanders so badly because it fails to uphold the courage of its convictions. Something is definitely off about the whole enterprise. Where it should be a lethally funny attack at the cliches of the Hollywood system, it holds no true insight or daring. And where it should be a cute romance, it is--for lack of a better word--sterile. Director Joe Roth may be the head of the promising new studio, Revolution Films, but as the one in charge of "America's Sweethearts," he has wasted the talents of a large bevy of people who probably should have known better in the first place.