Twelfth Night, Open Air Theatre, Regent's Park, London

A whimper of a storm puffs Twelfth Night on to the Regent's Park stage - and almost immediately the prospect of a night of yearning romance and laughter is blown away into the bargain. It's very much a case of set fair (to middling) for Timothy Sheader's opening production of the 2005 season at the Open Air Theatre.

A whimper of a storm puffs Twelfth Night on to the Regent's Park stage - and almost immediately the prospect of a night of yearning romance and laughter is blown away into the bargain. It's very much a case of set fair (to middling) for Timothy Sheader's opening production of the 2005 season at the Open Air Theatre.

The setting - an outpost of the Spanish Empire - brings out little in the play, particularly when so many of the characters remain irredeemably English. Martin Jarvis as Malvolio, in particular, is that most English comedy character, the municipal sitcom jobsworth. With his one concession to Spanishness, a Zapata moustache, he chases around inexplicably blowing a whistle and looks for all the world like a football referee from the Mexico World Cup circa 1970.

In places there is an almost ferocious amount of acting going on. James Loye's Andrew Aguecheek, for example, with his willingness to throw a pratfall at the drop of a banana skin, seems to be in perpetual motion.The more insecure comedy performances are only exacerbated when the confusion of identity is racked up toward the climax. A bout of limp, pat-a-cake stage fighting does not help proceedings.

The most rewarding performances are those that spring from a deeper sense of truth: Sirine Saba's overwrought, cheroot-smoking Olivia; James Millard's hollow-eyed, grief-wracked Sebastian. Mariah Gale as Viola has an exquisite scene in which Daniel Flynn's boorish Orsino sounds off and she fights her tears (manfully, of course) as her love for him bursts forth. Here, the play aches as it should. The exception to this is Desmond Barrit, who once again pulls off his high-wire act (as he did when Falstaff for the RSC) - balancing a bit of Oliver Hardy with a little Frankie Howerd and a lot of comic audacity as Sir Toby Belch.

The rich-voiced Simon Day as Feste the fool would, of course, have been barking up the wrong tree had he gone for total realism, but his dry wit and blend of jadedness and benign tolerance lend him a compelling truth. The designer Jessica Curtis has, however, created a witch-doctor look for him that is, if not distracting, then at least confusing.

Composer Corin Buckeridge's incidental music and settings of Feste's songs are emblematic of this confusion. The music is sweet and rhythmic, but would be more at home in the Havana bar across town in Guys and Dolls. Then, where confusion would enhance the production - the deliciously rich seam of sexual confusion - it is merely winked at coyly in a brief scene in which Orsino kisses Viola while he still believes her to be his servant Cesario, and abandoned thereafter.

Although not without engaging moments, it is, in the main, an evening of such missed opportunities.

Booking to 1 September (0870 060 1811)