Oh, Mamma Mia, here we go again: the Matilda producers are inviting critics to any one of a series of previews, with an embargo on all reviews until 25 November, carrying on as if they were in New York which, thank God, they are not.

This arrangement creates muddle and confusion and there's absolutely no need for it, apart from cravenly allowing the Sunday newspapers in to the show in the early part of the week so they catch publication on the last Sunday of November before the Christmas rush.

And now the Menier is following suit with its Pippin premiere in the first week of December, offering critics a choice of seats on the Monday, Tuesday or Wednesday (the official opening night).

This doesn't solve the clash of dates problem -- Pippin, if my memories of the London premiere directed by Bob Fosse are anything to go  by, is slight verging on mediocre -- as Monday marks the opening in Sheffield of Daniel Evans' revival of Company (oh dear, more Sondheimite hysteria), and Tuesday heralds Eddie Redmayne as Richard II at the Donmar.

And as for Wednesday itself -- why, that's the long-booked West End opening of the new musical The Ladykillers with Clive Rowe in it; and if he wasn't, he'd be in Company or Pippin, probably. That week's Thursday opening is the new Joe Penhall play at the Royal Court, something I'm really looking forward to  -- and Friday has that weird Flemish company, Ontroerend, abusing the audience at the Soho Theatre. And still no let up: there's even a Saturday press opening of Simon Callow in A Christmas Carol at the Arts!

The seating of critics has become an issue again lately, too, with seating offered in the middle of rows rather than at the end of the aisles. The argument is always that you have a better view of the stage from the middle of the row.

Which begs the repsonse: if the designer hasn't taken into account the sight-lines and the customers sitting on the end of a row then he's done a bad job. There was always this problem espcially at the Royal Court, but over the years most critics always made allowance for the peculiar box-like properties of that beautiful small stage.

The argument for sitting at the end of a row is always one of convenience: most critics shuffle notepads and have the sort of clobber -- briefcase, plastic bags, crampons and spirit level -- that most ordinary theatregoers do without. It's much better for all concerned if the scribblers are removed to the periphery, where they can spread themselves more comfortably and reduce the level of irritation to the rest of the house.

And it can't be very pleasant for practitioners, especially those directly involved, to find themselves wedged up against critics, as did both author and director of The Last of the Duchess at the Hampstead Theatre the other night.

Nicholas Wright, the author, and his partner David Lan, director of the Young Vic, found themselves next to Kate Bassett of the Independent on Sunday, while Richard Eyre, the director, found himself next to Ruth Leon.

Even worse, the great playwright Caryl Churchill, whose career as a theatre writer (after years on radio) was effectively kick-started by Nicholas Wright in the Theatre Upstairs, was next to me! And on the other side of me, I had the producer Eric Abrahams and the playwright Rebecca Lenkiewicz, both of whom were gushingly fulsome in their "congrats" to Wright (who was plonked right in front of me) at both the interval and the end.

I enjoyed The Last of the Duchess enormously. It's a stylish and entertaining look at celebrity culture, and the practicalities of journalism in  pursuit of its quarry. Anna Chancellor is tremendous as Lady Caroline Blackwood, the well-connected alcoholic society dame -- and wife of both Lucian Freud and Robert Lowell, though not simultaneously -- who was commissioned by Francis Wyndham to write a profile of the Duchess of Windsor for the Sunday Times colour magazine (as it used to be called).
 
Nor did it matter that neither Maggie Smith nor Vanessa Redgrave -- both rumoured to have been approached -- was playing the keeper at the gate, the Duchess's companion, Suzanne Blum. Sheila Hancock is wondeful in the role, mixing comic grandeur with defensiveness until she is sucked into the play further as the quarry herself.

The whole evening is a feast of high class comic acting, in fact, with Angela Thorne as a glorious Diana Mosley and the remarkable John Heffernan as a factotum with a hidden agenda. The loveliest touch of casting of all, though, is surely that of Conrad Asquith -- member of the aristocratic Asquith family, and brother of the writer and cartoonist Ros Asquith -- as a French butler.

Asquith doesn't have to turn a hair to imply his inbred supriority as a member of the lower classes, and he slopes on and off Anthony Ward's superb setting with the air of a man who couldn't be surprised, or dismayed, by anyone or anything. And he doesn't even have to adopt that phoney Jeevesian air of smarminess that was the trademark of the late, great Dennis Price.