Opera La Boheme Royal Opera House, London

They're poor and cold; she's sick and needs warmth. Yet Rodolfo and Mimi stay together over winter; by spring, she's dead. That's La Boheme. For all their differences, the two casts that the Royal Opera has so far fielded to open its final season in the house this side of the millennium have the same effect: it's time to say goodbye to this 22-year-old production. Presumably because the designs now look so tatty, the lighting has to remain dim, out of tact. As a result, a lot of John Copley's telling production details remain inscrutable, unless you're near the front.

Saturday's first night seemed endless, for which the conductor Christian Badea (standing in for an indisposed Charles Mackerras) must take the blame. When his conducting wasn't lethargic, it was lurid; occasionally (the last bars of Act 2), it was both at once. At least Monday night's conductor, Jan Latham-Koenig, kept things moving briskly along.

Saturday's cast made a hash of the work's comedy but were sounder on the drama: Luis Lima was not in good voice, but you believed his Rodolfo was as ardent as jealous. In the same role on Monday, Richard Leech, crippled by a wig that screamed "insincere", was a more boyish lad: the business with the violets, that shows up his possessiveness, went for nothing.

Their Mimis were ill assorted: the Latin lover got the English rose, Amanda Roocroft, in her first, brave and touching stab at the role; the innocent "Wasp" encountered a knowing Romanian minx, Leontina Vaduva, whose mastery of every sensual nuance reflected her familiarity not just with this role, but with Puccini's earlier Manon.

The first cast was led by its Marcello: William Shimell dominated the stage effortlessly. Judging from his contemptuous curtain-call, however, praise may not be what he needs right now. Elizabeth Futral was miscast as Musetta: with Handel, Bellini and Rossini behind her, and Lucia at the Met ahead, she understandably conserved her small voice and was often inaudible. The second Musetta, Cynthia Lawrence, was on a more appropriate, Puccinian scale. Noteworthy contributions were made by the first Schaunard (Paul Whelan), the second Colline (Sorin Coliban), the second Benoit (Francis Egerton) and the second Alcindoro (John Dobson). Jason Howard remained outside the role of Marcello on Monday: perhaps, like the audience, he too needed a new production.

After Saturday's opening night, I fear I started to wonder about opera itself: what with Jonathan Miller's moribund Traviata at ENO in the same week, it seemed the genre itself was suffering from autumnal damp and mould. What were we all doing, sitting through musty revivals, spectators at sopranos' slow deaths? And yet there were moments in Monday's second Boheme that made it all seem worthwhile, if not quite respectable.

Further performances of 'La Boheme' at the Royal Opera House, London WC2, tonight, tomorrow, 23-26, 28 Sept, 4, 8 Oct. Booking: 0171-304 4000