Polly needs more pizzazz

Farting, noisy micturition, sharting (a fart with follow-through), sweat, Irritable Bowel Syndrome, pizza grease, peanuts marinated in urine, burst spleens - this is the stuff Ben Stiller comedy roles are mostly made of. This is the actor who inadvertently turned semen into hair gel while wooing Cameron Diaz in There's Something About Mary, and who played a male nurse called Focker in Meet the Parents.

So, scatology, embarrassment and double-entendres are as key to his comic method as neurosis is to Woody Allen, or the pratfall to Charlie Chaplin. Indeed, in a series of gross yet high-grossing films, Stiller has become the face of contemporary American comedy.

But how funny is he really? With his right-angled ears, neanderthal brow, and blocky body, he has the nervous energy of the physical funnyman; there's a sense about him of a man ever-constrained by a resistant environment, he is dis-eased by the world. And there's the bafflement his doggy brown eyes express, time and again, when events conspire to show him - and us - that he is a mere plaything of fate, condemned to witness a chaotic world over which he can have no control.

The Stoics said that man feels most free when he is compelled to perform that action which he wishes to do. Thus the Stiller persona is always crucially unfree, and in his bondage he enacts those moments of sublime embarrassment which annul the social contract.

In Along Came Polly, Stiller plays Reuben Feffer, a risk assessor for an insurance company, whose neuroses perfectly mirror his job. We first meet him preparing for his wedding, and admonishing the party planner - who has mistakenly polished the dance floor - with statistical angst: "Thirty-eight per cent of the guests are over 70, which means there's a 27 per cent risk of a hip injury should they slip and fall."

Feffer is, we gather, determined to avoid risk in his own life; everything has been analysed and quantified, not least his choice of partner, Lisa (Debra Messing, Grace, from TV's Will and Grace), a nice Jewish girl and a real-estate agent to boot.

The wedding goes off without a hitch, but within hours of arriving in St Bart's for their honeymoon, Reuben surprises Lisa being pummelled beneath the risky bulk of Claude (Hank Azaria), a cod-Gallic scuba instructor. As he ruefully remarks later to his best man, Sandy Lyle (Philip Seymour Hoffman), "They still had their flippers on".

Back in New York, Reuben, at Sandy's instigation, immediately embarks on putting his life back together again. And at the very first party he attends - a modish art opening - he meets an old friend from junior high, the Polly of the title (Jennifer Aniston), a wacky free spirit, whose determination to move on geographically is matched only by her commitment phobia.

So far, so well set up. Yet from here on in Along Came Polly degenerates into a tension-free zone of lame gags and a limping plot line. All I wanted out of this film was a scant 90 minutes reprieve from the dolour of a wet February in London, and all I got was a sense of irritation and torpor.

The script is the main problem. Well, the script and the direction, and the same man, John Hamburg, stands accused of both crimes. The central conceit is fine: anal meets oral, and the opposites attract despite their initial revulsion. But the prophylactics placed in the path of true love are all too easily ruptured: Lisa's return, the bathetic antics of Sandy, Reuben's embarrassing mother, and a subplot involving a risk-addicted Australian tycoon (Bryan Brown); while the apparent incompatibilities of the duo are just that, and melt away easily under the hot sun of their true love.