There's a lot of curious cross-national casting going on in Lisa Cholodenko's "Laurel Canyon," a dysfunctional family dramedy about a lifestyle collision between a pot-smoking, fast-living record producer and her solemn, starchy Cambridge-grad son.

Jane, the party-hardy, pushing-50 mom, is played with flaky roach-clip laissez-faire by the droll Frances McDormand -- who is the only person in the cast using her own accent.

Brit Christian Bale ("American Psycho," "Reign of Fire") puts on an American brogue to play Sam, the son endlessly irritated by his mom's lax attitude toward life, who nonetheless returns to her swimming-pool and music-studio hideaway in the Los Angeles hills, along with his fiancée, when he accepts his first residency at an area psychiatric hospital.

The beautiful Kate Beckinsale ("Serendipity"), who is also English, plays blue-blood bride-to-be Alex from New England, a genetics grad student working on her dissertation and suffering from inborn ennui -- which is put to the test when she's enticed down the rabbit hole of Jane's alluring rock'n'roll lifestyle.

Cast as Jane's swaggering, 16-years-younger rock-star boyfriend from England is American actor Alessandro Nivola ("Mansfield Park," "Jurassic Park III"), whose character further distracts Alex from her genomes paper and her buttoned-down existence. Meanwhile Irish actress Natascha McElhone ("The Truman Show," "Solaris") does the same to Sam, playing a flirtatious Israeli hospital resident who wears her sexuality on her sleeve.

I'm sure there's an interesting story behind all this accent-swapping, but the novelty of it is probably distracting only to those who know all these actors well (i.e. movie critics). Of larger concern to most moviegoers may be the fact that the film is well-acted but unadventurous in its allegorical depiction of temptation and personal growth.

Cholodenko ("High Art") sets the stage with the opening scene of Sam and Alex having routine, goal-oriented sex, then sets them up to both discover conveniently simultaneous external attractions.

Sam tries to resist sexy McElhone's coy come-ons. "Sarah, I think we should take the high road...sublimation," he tells her. "That's not very honest," she replies, "and not very satisfying." Meanwhile, Alex's inhibitions are dropped far more easily, almost culminating in a three-way tryst with Ian and Jane.

Bale and Beckinsale are well matched as a bottled-up young couple hitting a rough patch due to external stimuli. As he's being driven to live conservatively by a burning desire to be nothing like his mother, she's discovering a mild cache of wild oats she never knew she had. McDormand is especially good, exposing the selfish shortsightedness of her character's free spirit while maintaining a suppressed insecurity beneath it all. And Nivola makes a convincing devil-may-care rocker, both in out-sized personality and vocal ability.

But "Laurel Canyon" is held back by its predictable story arc, by overt metaphors (Alex's dissertation is on the sex lives of fruit flies) and by symbolism that betrays a lack of sophistication at the script level (Alex abandons her designer track suit to go jogging in one of Jane's ratty old concert T-shirts), which good performances can only partially overcome.

Cholodenko's characters remain three-dimensional and easy to care about, but they're often hard to sympathize with. I mean, if Sam can't stand his mother, why did he want to move back to Los Angeles in the first place?