First Night: Blandings, BBC1, 6.30pm

If you're adapting PG Wodehouse for the small screen, there's no way you can avoid competing with the gold-standard set by Clive Exton's versions of the Jeeves stories back in the 90s, which starred Fry and Laurie and captured the disciplined frivolity of the prose with a loving accuracy. But you really should avoid competing with the author himself.

Sadly, there were several moments in the first episode of Guy Andrews' Blandings where it seemed as if that was exactly what was happening. On this evidence, the series is a long way from a disaster. It has a fine cast and last night's opener included several very funny moments at which you caught the authentic glint of Wodehouse's comedy. But it was also padded out with extraneous incident in a way that made you feel they hadn't quite trusted Plum to do the business.

To be fair, a little like Lord Emsworth's pig The Empress, the original story needed some fattening to make it show weight. The tale on which it was based – "Pig-hoo-o-o-o-ey!" – is a slender affair that doesn't even feature Freddie Threepwood. So it wasn't completely out of order for Adams to add some bulk. And at its best it seemed likely that he was using peelings from other Wodehouse writings to do it.

"So persuasive", mused Lord Emsworth about his redoubtable sister Connie, "She once put forward such a forceful case for beetroot I actually put some in my mouth." I don't know whether that's Adams' line or Wodehouse's, but it has the authentic literate gleam of the master either way. As did Emsworth's sorrowful self-description at a low moment: "Behold your father Frederic. A toad beneath the harrow." Timothy Spall clearly relished the opportunity to wrap his assumed RP round those phrases. And while he's nobody's idea of a natural aristocrat, he can weight a funny line perfectly. Jennifer Saunders was on good form as Connie, too.

But elsewhere, there was the worrying sense that they felt Wodehouse needed a helping hand if he was going to make the audience laugh. There was too much laborious slapstick – mostly involving Freddie Threepwood bumping into things – and added plot complications which took up space that would far better have been given to missing gems from the original.

When Beach the butler refuses to perform the universal pig-call which will coax The Empress back to her swill, for example, the adaptation simply moves on.

In the story he's won round, but only on condition that they move out of earshot of the servants' hall. "If I were to be overheard by any of the lower domestics it would weaken my position as a disciplinary force," he says, grandly – a line Mark Williams could have delivered with a wonderful mullet-lipped froideur.

Most grievous of all, somebody had at one point mixed in a cartoonish comedy sound effect to underline a joke – as if Wodehouse's comedy is a comic-strip affair, rather than a lovely collision of the highest style with the emptiest content. As television it wasn't bad at all. As Wodehouse, it wasn't quite good enough.