There's no brighter presence in movies today than Amy Adams, who bounds onscreen with such infectious charm that she at times recalls the sunny starlets of a bygone era. So in that sense, she's completely at home in the thin period farce Miss Pettigrew Lives For A Day, starring as a ditzy, incorrigibly flirtatious young woman who wants to be an actress, and hails by the whimsical stage name Delysia. Adams is the sole reason to bother with this flimsy time-passer—which perpetually appears to be funnier than it actually is—but not an inconsiderable one, given how many scenes are offered up for her to steal. But in trying to recapture the spirit of classic '30s screwball comedies, the film too often mistakes manic energy for wit, and it ends on a note of gloppy sentimentality that wouldn't have held water in Old Hollywood.

Trying a shaky British accent on for size, a never-worse Frances McDormand stars as the title character, a shabby "governess of last resort" in pre-World War II London who can no longer find work looking after rich people's kids. In a desperate bid to dodge destitution, McDormand follows a referral to a luxury flat and immediately gets caught up in the maelstrom of Adams' romantic life. For various reasons, Adams is hooking up with three different men: the flat's extravagantly wealthy, rabidly jealous owner (Mark Strong); a young slickster (Tom Payne) with connections in the West End theater world; and a humble pianist (Pushing Daisies' Lee Pace) who has only love to offer her. After admiring McDormand's instincts under pressure, Adams immediately hires her to manage this circus as her "social secretary."

Director Bharat Nalluri, working from Winifred Watson's novel, succeeds in keeping the frantic day-in-the-life goings-on fizzy and light, but there's a difference between ebullient and inconsequential. Adams stays on the right side of the line, as does the fine character actor CiarĂĄn Hinds, who exudes relaxed confidence as a successful designer who takes an interest in McDormand. But there's little imagination in the film's artificial, back-lot-tour vision of London, and little surprise in how the complicated plot finally untangles itself. Why bother with a mannered facsimile of an old-fashioned screwball comedy when the real thing will do?