Les Patineurs / Tales of Beatrix Potter, Royal Opera House, London

A happy, sparkly Frederick Ashton double bill that, sadly, made one leave the theatre dreaming of mousetraps

Before Strictly and the ballroom boom, it was figure-skating that won the British armchair vote for dance. And since the heyday of Torvill and Dean (I note the veteran duo are giving skating arenas another whirl just now), the phenomenon of temporary public outdoor rinks has taken off.

But it was in the 1920s and 1930s that skating had its major fashion moment, and it was surely no coincidence that Hollywood's biggest-grossing skating picture, Thin Ice, appeared in the same year, 1937, as Frederick Ashton's skating-party ballet Les Patineurs, currently revived at Covent Garden.

If there is a happier, sparklier item in the Ashton rep, I don't know it. Created to show off the virtuosity of the fledgling Royal Ballet, its cleverness lies in largely ignoring ballet's aerial qualities to focus on terre-à-terre steps that replicate the push, glide and sashay of effortless movement on ice.

On opening night, though, not all of the 13 "skaters" on William Chappell's tree-fringed frozen pond had caught the required nonchalance of that sashay. Some turned it into mincing, so that moments of humour misfired, most markedly in the case of the elegant couple who take an ungainly tumble, then swiftly reposition, stick their noses in the air and glide on. Wit is guaranteed, however, at every entry of the Blue Girls, Yuhui Choe and Laura Morera, as they stomp across the rink en pointe, swinging arms in sync, and turning their heads to smile at us like pert clockwork toys.

Part of the joy of this ballet comes from the costumes, credibly snug and furry, yet so dazzling in their detail that they almost dance by themselves. The Brown Girls' outfits are covered with tiny white balls, trimming the peplums on their jackets, their bonnets, even their socks. Poor Sarah Lamb, the Snow Queen of the piece, is so tiny she almost disappears into her powder-puff frock. Yet still she exudes ineffable 1930s glamour.

But the real star is the virtuoso Blue Boy – Ashton's answer to Petipa's Blue Bird in The Sleeping Beauty – who is challenged with sustaining, at length and extreme speed, the kind of spins that ought not to be possible without blades. Earlier in the piece, as the first-cast Blue Boy, Steven McRae slices zigzags from the air with beaten jumps as sharp as icicles. By the end, when he tackles that fiendish spin, his appearance has generated such expectation that the audience erupts.

While Les Patineurs feels short at 24 minutes, its companion piece, the hour-long Tales of Beatrix Potter, sags like the jowls of the giant sow, Mrs Pettitoes (a minor character whose mumsy outer casing, according to the cast sheet, concealed the splendid Eric Underwood – what a waste!). The terrible truth is that Tales, now hauled into annual service as a child pleaser – could have been a better ballet if Anthony Dowell, who adapted it for the stage, had edited with a firmer hand. (Ashton's dances were originally made for a film, and revel in delicious ballet in-jokes: the mouse waltz that turns the ribbon-play of Ashton's La Fille mal Gardé into a skipping game with mousetails; the arm-rippling exit of Jemima Puddleduck in the style of the Swan Queen.)

Out should have gone the tedious squirrels, whose ginger-furred padding makes a fumbling nonsense of the dancers' neatest efforts. Out, too, should have gone half those pesky mice. Yes, it's marvellous how the masks make their human hands and feet look tiny, the steps even daintier than they are, but the effect soon palls. Something is wrong, is it not, when one leaves a theatre musing on mousetraps?

In rep to 13 Jan (0207-304 4000)