Things are going from bad to embarrassing. Having been hailed as Benedict Nightingale by Arthur Smith at the Critics' Circle awards, I edged my way through a packed dress circle bar at the Duke of York's on Saturday night to be greeted with "Hello, you're that Charles Spencer..." by a merry but undiscerning punter.
 
As I dived into the gents, I could hear hectic whispers of, "No, it's the other one, Michael Whatsisname..." so at least they'd narrowed it down to Billybong and me.

It was a name-sensitive sort of evening, as I'd already received an email from the show's publicists reminding me how to spell the name of the actor playing Robert Ross in Neil Armfield's spectacularly well-directed Hampstead Theatre production of David Hare's The Judas Kiss. As I've covered this actor's work for thirty years, I was a bit put out by the impertinence.

But a glance at the programme explained the intervention. All proper names are printed in block upper case, so CAL MACANINCH could represent Cal Macaninch, or Cal MacAninch (the correct spelling) if you were new to the job, or a bit sloppy.

The Judas Kiss, in which Rupert Everett as Oscar Wilde is giving a stupendous performance in a play that has been transformed, really, since its premiere in 1998, opens "officially" on Tuesday. Yes, it's one of those irritating "come when you like" press invitations over the last few previews (and reviews embargoed till Wednesday, after the real first night, which now becomes a sort of self-regarding gala).

This drains the performance of a "special" feeling, but it does make you notice things like: no ushering in the stalls, astonishingly; horrid coffee in paper cups (yes, the Duke of York's is an ATG theatre); over-priced drinks and eager but inexpert bar service; a forlorn "Veuve Cliquot" station in the tatty-looking foyer; oh, and programmes costing £4!

That said, Saturday night's audience was admirably attentive, all the way to the top of the theatre, where they were packed like sardines in the gallery. And the show was taut, tight, sharp as knives and would seem to have "hit" written all over it; it will be interesting to see how it fares in this snowy cold snap period.

Incidentally, I asked Julian Bird, head of SOLT, the Society of London Theatre, at the Critics' Circle awards, why we couldn't have box office receipts published up front, as they do in New York, so we could believe what managements claimed about commercial performance; he simply said that we have a tradition here of building audiences even for shows that are failing, and it takes time, which is no sort of answer at all, is it?

Slithering around town on Friday night and fetching up at the Grant Museum of Zoology next to University College Hospital, I asked Jonathan Miller if his idea of heaven was a roomful of theatre critics, but he said that as he hardly knew any of them any more, the question was invalid.

Right on cue, enter the old guard, Benedict Nightingale and John Peter, and Miller's hackles rose perceptibly, but only to be civil and friendly; this was, after all, an occasion designed to honour, not berate, him, the publication party for Kate Bassett's fine biography - though it tails off towards the end - In Two Minds.

He was even blessed with two Tom Sutcliffes: the Independent columnist, and the former Guardian critic who was once a sworn enemy of Miller but who came round to admire him, thus providing one of the minor stories in the book. Other, more intransigent adversaries, such as Michael Billington and Peter Hall, were notably absent.

Hall's name cropped up, nonetheless, when Michael Blakemore told me that his new book, Stage Blood, coming out in September, will reply at last to what he regards as unfair, and untrue, remarks about him in the Peter Hall Diaries; he will be addressing, too, the way in which he feels Hall turned the National Theatre project into a personal mission instead of a public service.

Blakemore also thinks that the first five or so years of the NT Olivier era at the Old Vic have been much underrated. That is when he and Miller were in their pomp as NT associates. Putting records straight is not always the most pleasurable reading, but Blakemore is such a good writer that he'll find a way of making it just that.

Other big beasts at the party (drinks, but no nibbles, alas) included the great journalist Neil Ascherson, documentary film maker Roger Graef, actor Peter Eyre (who played Hamlet, Konstantin in The Seagull and Oswald in Ghosts in Miller's superb "Sons and Lovers" Freudian season at Greenwich nearly forty years ago), Rhoda Koenig, Times journalist Alan Franks, photographer Nobby Clark and Barrie Rutter.

It was Rutter's idea to invite Miller to direct the forthcoming production of Rutherford and Son for Northern Broadsides, and you can't help feeling that it marks a return to the sort of informal, flexible theatre-making that Miller imbued with such intelligence and freshness in his early years with Kent Opera and subsequently at the National and the Old Vic. I certainly intend to be present at the first night in Halifax next month; and I shall go a day early, too, in order to catch FC Halifax Town play Harrogate at the Shay (if the pitch isn't frozen) the night before.

Miller had family and grandchildren with him, and seemed relaxed, though he admits he hasn't read Bassett's book and probably won't. After formal speeches he took the floor and revealed that in this very room, and indeed on the very spot where he now stood, he first sat and studied for his medical exams; this was the University College Hospital library, unadorned in those days with the spooky skeletons, stuffed pterodactyls and theatre critics - who could tell them apart? - now festooning the panelled premises.

He studied fruitfully, winning the scholarship he needed to pay for his training, and indeed to get married to Rachel, whom he had known since she was seventeen. Rachel, now retired, trained at the nearby Royal Free before becoming a GP. Then, of course, Miller was, as he always says, "seduced" by show business, mainly through his name-making success with Beyond the Fringe fifty years ago.

He told us how the producer, John Bassett (no relation of Kate), had signed up Alan Bennett and Dudley Moore from Oxford for the revue commissioned by the Edinburgh International Festival (Beyond the Fringe was always beyond it) and, wanting Miller, asked him if he could recommend another Cambridge comedian to make up the quartet.

And of course Miller dragged along Peter Cook by whom, he said in a moment of sudden tenderness, he was always "dazzled." He recounted how Cook used to sit behind a newspaper in busy Footlights sketches and drop in occasional remarks like, "I see the Titanic's gone down again, then"... and that, said Miller, was exactly the sort of thing everyone wanted in the show.