Joy Zipper, ICA, London

Joy Zipper are like raccoons: they're so cute you want to pet them, but they've got a bite.

Joy Zipper are like raccoons: they're so cute you want to pet them, but they've got a bite. On stage, the singer-guitarist Vinny Cafiso shyly peers out from under his floppy fringe, doe-eyed and dopey, while Tabitha Tindale, his real-life and musical partner, is apple-pie blonde and impishly perky. Then the Long Island duo go and sing songs that smuggle in to their sweet surface textures themes of suicide, the mixed benefits of hallucinogens, and getting stuck growing old with a partner who makes you sick. Their last and second album was called American Whip, and they certainly laced its ice-cream ambience with something spiky.

Tonight, though, it's the cuteness that has to carry it. The Zipper aren't in sturdy live fettle and, in fairness, they know it: Cafiso pleads a month's near sleeplessness in his defence, due to US touring duties, and they're pretty much fresh off the plane from LA. Their schedule hasn't given them much time to cook up a fresh set, either, most of tonight's gig being made up of tracks from Whip rather than their forthcoming third record, the excellent The Heartlight Set (recorded at Vintab Studios. Aw.).

But they probably haven't quite nailed how to translate live yet, as well. On record, Whip is a lush dreamscape, setting bright-eyed harmonies and lively melodies against lazily velveteen textures. Padded out to a basic four-piece, the Zipper get stuck halfway tonight, suspended between a rock band who are too dreamy to rock and a dream-pop band who aren't hitting the right woozy groove. "Dosed and Became Invisible" is a deliciously druggy drone-pop number on album, but live, it just drones; likewise, the suicide song "Valley Stream" has to settle for soporific rather than unsettlingly seductive. The sound is stodgy, too, prompting much anxious gesticulating to the sound man from the duo.

Still, nervousness sort of becomes Cafiso and Tindale. They sound better when they're harmonising on vocals than when they're - somewhat shakily - singing separately. Winningly, too, Cafiso even has the cheek to ask the crowd to cheer louder just to make him feel better. It all goes to create a sense of intimacy that swings proceedings their way, even though they know they're on a losing streak. ("You're too kind," says Cafiso in response to the applause. You kind of agree, but clap anyway.)

Sonically, they're at their best when they strip out the stodge and build the songs up from their bare basics. The strongest tracks are the clear-eyed and clean Heartlight numbers: the languid, lovely "Thoughts a Waste of Time", the ramalama-billy clap-a-long of "Go Tell the World". Neither sacrifices Cafiso and Tindale's trademark dreamy airs, but they are more direct than the Whip songs, allowing the duo to breathe a little. Once they've toured it for a while, Heartlight might well be the album that pairs Joy Zipper's genuine likeability to a proper set of live teeth.