Dylan Moran is hilarious; I plan to go again when he next visits Oxford.

His verbal pyrotechnics are still fluid, his baffled rage still vigorous, his dishevelled stage persona still shaggily adorable.

The New Theatre was predictably packed: "I'm glad you're all here. Of course you're here. What else is there to do in this fucking town?... This cultural hole... The Ashmolean Pubic Hair Restrospective."

His classic chains of quirky images come hard and fast and keep the audience rolling about with laughter: giving up smoking is like wrestling a polar bear; it's wonderful to be alive in this world of.. skateboards! And toast! Instead of watching the news, he proposes to employ one old man to shout "Terrorist!" every half an hour, and another to shout "Paedophile!" and then a woman to walk between them with the weather report.

And yet the glinting edge that keeps me up late too often, giggling dementedly on the sofa over my thousandth viewing of the Monster tour video, is less in evidence than it used to be. I don't know if he just happened not to be on top form tonight or whether there's more to it than that. But I suspect it's possible that Dylan Moran's top moments as a performer are incompatible with his comfort as a human being. His act used to blaze with a certain sense of imminent disintegration, the heady, awful, Saturday-night downwards spiral of the chainsmoking alcoholic of Black Books. Now, with a functional family life (despite his constant battle with the polar bear), the sphere of his jokes has been subtly shifted to that of the Guardian reader. Getting older, getting fatter, being intimidated by hipsters, trying to find something vegetarian to eat in Germany. These are things other people can be funny about, not the coruscating free-wheeling nonsense that used to be his trademark.

Don't get me wrong: he's still really good. But he seems less comfortable than he used to be with his rage, perhaps too conscious that he's got less than he used to have, less than others, to rage against. If comfort, parenthood and a social conscience really are effecting a change in his art, it seems most unfair. Anyway, as I say, notwithstanding comparisons with the past, he's hilarious and I plan to go again next time.