FILM / The comfort of strangers: Adam Mars-Jones on Manhattan Murder Mystery, Woody Allen's return to a familiar form and, in Diane Keaton, a familiar leading lady

It's light, it's droll and it's pretty much guaranteed not to feature on any newspaper pages except the ones devoted to the arts. From Woody Allen's point of view, Manhattan Murder Mystery must count as a total success, and audiences needn't feel short- changed either. The presence of a book called Romantic Comedy by the hero's bed is an ominous early signal, but what follows isn't excessively weighed down by knowingness or by movie references.

There are some formulaic scenes (woman searches man's room, for instance, hiding under the bed when he returns prematurely), with only an idiosyncratic choice of music - drum-based jazz - to lend a distinctive flavour, but there are also plot-driven sequences that have been thoroughly customised, and Allen continues to explore familiar scenes in the central relationship between Larry (Allen himself) and Carol (Diane Keaton). This is still the Manhattan of happy angst, of cosy discomfort and intimate irritation.

Larry and Carol have a rapport based on friction. Their bantering can turn to bickering without their really noticing the moment that they start getting on each other's nerves, or even the point at which other people would be calling their lawyers and discussing the distribution of assets.

In some ways Diane Keaton is an outstandingly fussy actress, with her repertoire of hesitations and nervous gestures, but she can also convey a natural sensibility under all the tics. Her Carol, a kook who's not so kookie after all, whose wild deductions turn out to be accurate, is almost a reprise of Annie Hall. Even her wardrobe, with its combination of the formal and informal, is reminiscent of Hall's - though these days it is more likely to emphasise the enduring excellence of her legs.

Allen's Larry, meanwhile, is a safely unflattering self-portrait. There are no young women around, and the only child in evidence is the couple's grown-up son. When Larry is tempted to stray, it is with a writer whose novels he edits (played by Anjelica Huston), and he is half-hearted about it. He is only trying to console himself in advance for the possible loss of Carol; it's an anticipated rebound.

There's more slapstick than there's been for a good while in a Woody Allen film, and a purer incarnation of a schlemiel in the hero. Early in the film, we hear the absurd clatter in the dark of the lifelong wearer of glasses fumbling for them in order to answer the phone, unable to contemplate consciousness without corrective eye wear. Larry is neurotic and unadventurous, immediately giving the game away with a sort of hyperactive clumsiness whenever he is called upon to lie or act a part. The man is a walking polygraph. Perhaps there's a slight extracurricular emphasis to his line, 'I don't break the law, I live within the Constitution.'

It's a familiar pattern in Woody Allen movies for the Allen character to be first torn down and then built up, made first comic and then romantic - most jarringly in Hannah and Her Sisters, where it skewed the structure of the whole film. In Manhattan Murder Mystery, this development is integral to the narrative: if Carol starts informally investigating a neighbour's death partly as a way of growing away from her husband, and of sharing something with an old friend (Alan Alda's Ted) who also seems to be making himself romantically available, then Larry must show his competence in this precarious public realm to prove himself worthy of her after all.

Never mind that from the audience's point of view, it's not actually in doubt that Carol and Larry belong together. Not only have they exchanged vows, they've exchanged exclamations, so that in moments of crisis he says 'Jesus]' and she says 'Oy veh]' The mild twist that Manhattan Murder Mystery adds to its generic forebears - the various Thin Man films, where sleuthing was the extension of a glamorous romance - is that here the investigation is a sort of DIY marital therapy.

The script, written with Allen's early collaborator Marshall Brickman, has a feel of something taken out of mothballs and brushed up with a few up-to-date references (a mention of the fashionable anti-depressant Prozac is the closest thing to topicality).

The understandable move away from the public domain, where Allen has had to spend so much time lately, has one unwelcome side-effect. When an artist is dealing with his own life, in however veiled a way, the issue of narrowness needn't arise, but when he shifts focus and starts dealing with people who are vaguely similar to himself (but without his particular history), then his can seem a very inconsequential vision. The mildly creative people, secure in their unease, who populate Allen's films, can seem uninteresting when there is no prospect of a jolt of confession or self-discovery. Even the incidental people who walk the pavements in Manhattan Murder Mystery look curiously homogenous and interchangeable. Autobiographical material was only one of the things that made Annie Hall such a breakthrough film for Woody Allen. There was also his discovery of his own playful way of using the camera. But that is something he has only intermittently consolidated. He is often tempted by pastiche, in a way that suggests an insecure sense of his identity as director.

For his last film, Husbands and Wives, he chose to use a jarring pseudo-documentary style, the film language of a pretentious film school graduate. Manhattan Murder Mystery has only one similar moment, where the camera zooms towards characters' faces with an amateurish lurch, but there is still a feeling of disingenuous roughness. Conspicuously hand-held camera-work can seem like a tiresome affectation in the era of the Steadicam.

The relatively anonymous style of the film is suddenly overtaken at its climax by a curiously inappropriate hommage to Orson Welles. Having contrived a showdown behind the screen of a run-down cinema in a space already full of mirrors, Allen makes it coincide with the film being shown: the final shoot-out in a hall of mirrors from The Lady from Shanghai. When it comes to an obligatory action climax, Allen can only borrow, without making the borrowings his own. However, Larry's verdict after the event - 'I'll never say that life doesn't imitate art again' - may be the simplest explanation for the new film's flight from the personal.

(Photograph omitted)