Last Night's TV - Just William, BBC1; Giles and Sue Live the Good Life, BBC2; All About The Good Life, BBC2; The Miracle Baby of Haiti, Channel 4

Clumsiness can be very funny indeed in the right hands, but there's something about badly simulated incompetence that kills comedy like a sledgehammer to the temple. There were a couple of notable examples yesterday, first in CBBC's new version of Just William (which featured a particularly egregious example of wobbly moped riding) and then in Giles and Sue Live the Good Life, a mystifying exercise in low-grade slapstick, which indulged Giles Coren's eagerness to throw food about to an actionable degree. The first programme went out at 12.30pm and was squarely aimed at viewers under 12. The second one went out way after the watershed and was, incredibly, intended for adults.

Just William was a good deal more bearable, coming with the recommendation of Daniel Roche in the title role (he also played the Williamesque younger son in Outnumbered), Simon Nye writing the script and Martin Jarvis doing the voiceover narration, as if they were knowingly passing the baton from one generation of Crompton interpreters to the next. The original stories, remarkably, spanned nearly 50 years of British social history, so you can pretty much take your pick of period. Here they have opted for the Fifties, which can certainly find textual sanction in the canon, but still feels slightly wrong. The world William inhabits – of irate gamekeepers and vicars and tea-parties – is solidly anchored in the Twenties, and begins to look a little hollow and unpersuasive when updated.

That's hardly likely to worry its target audience though, which Nye clearly feels may include a few nostalgic older viewers. The script, perfectly functional when the children were talking, seemed to perk up a little when they disappeared – even finding room for an amorous little exchange between Mr and Mrs Brown. The excellent Rebecca Front plays Mrs Brown and Caroline Quentin takes the role of Mrs Bott, salient here because it was the episode in which William first encounters Violet Elizabeth Bott, a simpering confection of tulle and ringlets with the lockjaw grip of a saltwater crocodile.

For an adult the laughs didn't come from the sight of angry gamekeepers stopped in their tracks by a muddy puddle they could easily step across (more ersatz incompetence), but the sound of Mrs Bott trying to get her aitches in the right place, or the attempted recovery of Mr Brown after he's precipitously answered "yes" to her question "Do I look like a panda?" "It's our favourite of all the bears," he adds placatingly. Incidentally, I don't know why it's assumed that children have the interpretive equivalent of myopia when it comes to facial expressions, but – with a few honourable exceptions – all the acting here is wildly over-amplified, as it all too often is in comedies for children.

Giles and Sue Live the Good Life was a festive special, loosely assembled around the notion of a do-it-yourself Christmas. So Peter Purves turned up to help the duo make a Blue Peter advent crown (cack-handedly naturally) and Sophie Grigson came to give them advice on cooking the Christmas dinner, a sequence that allowed Giles Coren to throw flour over people. Then they got drunk on homemade eggnog, chucking it around the living room and letting it dribble down their chins. A more depressing way to waste an hour of your life it's difficult to conceive and I wouldn't mention it at all but for the fact that Sue Perkins can be funny in such situations. Coren probably deserves to be incarcerated until they've got his Ritalin dose right and he's safe to release into society, but somebody needs to rescue Perkins from a format that's gone rancid. It was like the Chuckle Brothers – but without the sophisticated wit.

It didn't really help that it followed All About The Good Life, a slightly over-affectionate celebration of the Esmonde and Larbey sitcom, which nonetheless reminded you of how beautifully written and performed it was. Even the slapstick was nicely done. Apparently people are still so fond of the programme that they go on special pilgrimages to take pictures of the houses that were used for the exterior shots, which seems a bit extreme to me, but not, perhaps, to Brian Sewell, who appeared from time to time to add another fluting panegyric. "It's up there on its own little Olympus," he said. Apart from the writers themselves and Felicity Kendal, they seemed to have talked to everyone still available – from the man who designed the titles to the costume woman who provided Margo's endless changes of outfits. The programme itself was made when BBC floor managers still wore dinner jackets on set, but the jokes still had no odour of mothballs about them.

I confess I bridled a little at The Miracle Baby of Haiti, the title leading me to think that it would be a cheap tabloid exercise in sentiment. It told the story of Landina Seignon, a month-old baby who had been in hospital with bad burns when the building collapsed on top of her. Amazingly she survived and was eventually flown to Britain for the specialist treatment she needed to save her – a complicated and expensive business that raised serious questions about charitable instinct and practical priorities. Inigo Gilmore's film, to its credit, didn't just exploit the viewer's feelings, but showed how complicated their consequences could be.