It's not just a question of good and bad, it's all about context. Two productions of The Importance Of Being Earnest, Oscar Wilde's "trivial play for serious people"; two different theatres, two different audiences and, quite rightly, two very different productions. At Chichester, a handsome theatre peopled with handsome theatre-goers delivers the kind of handsome production you would expect. A comedy of manners as cool and crisp as a cucumber sandwich. A titbit to take with your tea. Nothing to upset the digestion.

Christopher Morahan's Chichester production plies all Wilde's wit but misses the subversive element by a mile. This one is not about sex, it is about society never more so than in Patricia Routledge's Lady Bracknell, quite recognisably the woman who later on in the play admits: "When I married Lord Bracknell I had no fortune of any kind. But I never dreamed for a moment of letting that stand in my way."

She knows the importance of the right degree of snobbery. But her clothes betray her. Decked out in purple and black beadings, she resembled a pair of curtains in deep mourning. Green and olive stripes for a visit to the country gave her the allure of a well-manicured lawn. She has none of the easy elegance of her born-and-bred-to-it daughter, Gwendoline (Saskia Wickham). In fact, Routledge's Bracknell is nowhere the "monster without being a myth" of performance legend. She is benign, a woman whose sense contrasts with the silliness of the next generation. They think love is about the heart: she knows it is about income and position in society. That's what makes life tolerable.

In Bolton, where the Octagon Theatre is fighting for survival as a production house, Lawrence Till bows out like many of his staff, made redundant with a production so thrillingly subversive it takes your breath away with the sheer, good-natured cheek of it. The lunatics have been let out of the asylum and have taken over the tea trolley.

And why not? When you're dangling over a precipice, why not go for broke and have lots of fun on the way? Like Till's reign at the Octagon, this production is distinguished by its ability to challenge and surprise. Mad but never bad, it's a piece of revolutionary nonsense in which the doubling of parts reflects double lives and double standards.

It's been suggested that Wilde's play was written in homosexual code. In Till's deliciously daffy, irresistibly camp production the characters cross gender as the play progresses - other codes operate too. A pram stands in the middle of an empty stage: a reference to the perambulator that causes Miss Prism so much bother, but also to the pram in Edward Bond's Saved, directed so brilliantly by Till a couple of seasons ago.

Then there are the copies of Lady Chatterley's Lover being read by both Algernon and Lady Bracknell, and the sofas in Jack's drawing room constructed entirely of play texts: plays that have been staged at the Octagon, others that will never be staged if its future is not assured. Some members of the audience will get these references, some may not. It doesn't matter if they do or they don't just as it doesn't matter whether they understand Wilde's encrypted message. The play succeeds both as a comedy of manners and as a revolutionary assault on Victorian values.

The beauty of Till's knowing production is its central dichotomy: all show and all hidden. Text and subtext, seriousness and silliness, it is as completely about sex, the possibility of transgression and the double lives of its protagonists as about society. You couldn't get two more different approaches, and there are no marks for guessing which is likely to end up in the West End. As Lady Bracknell herself might say, the West End isn't about context, it's about commerce.

• At the Chichester Festival Theatre (01243 781 312), till July 17. At the Octagon Theatre, Bolton (01204 520661), till June 5.