Madonna has not strayed behind the camera before

Filth and Wisdom a sprawling comedy, is a celebration of London's ethnic stew, and stars Eugene Hutz as a Ukrainian gypsy with an intensely annoying habit of looking the camera in the eye and spouting gobbets of wisdom that have as much relevance to real life as Chinese fortune cookies.

Yet despite its many shortcomings and an ending so mushy and neat it would embarrass Richard Curtis, Madonna has done herself proud. Her film has an artistic ambition that has simply bypassed her husband, the film director Guy Ritchie.

She captures that wonderfully accidental nature of luck when people's lives intersect for a whole swathe of unlikely but cherishable reasons. Altmanesque would be stretching the compliment too far, but Filth and Wisdom shows Madonna has real potential as a film director.

Ragged, uneven and pot-holed with some dire dialogue and performances, the film's cockeyed optimism and likable leads conspire to bring a smile by the time it's done.

Barely feature-length at 81 minutes, it likely will appeal to Madonna's fans for its echoes of various threads of her own life story and the grunge style of Desperately Seeking Susan.

To many, however, it will remain an oddity... Wisdom is unexpectedly sentimental, too, but the three leads are sufficiently engaging that while chaotic and more than a bit silly, the film in the end conjures up a surprising amount of goodwill.

This 80-minute film started life as a half-hour short and somehow more than doubled its screen time. I wished it hadn't as there are too many over-long musical montages and poorly executed scenes.

The comedy aimed at all ethnic groups often falls flat. The funniest scene sees Holly, in a school uniform, forcing a stripper dancing to Madonna's Erotica off stage while the DJ decides to play Hit Me Baby One More Time in homage to the Britney Spears video. The scene highlights the area where Madonna truly excels and unsurprisingly it is an excellent soundtrack.

On this evidence Madonna has a long way to go as a film-maker. To her credit, she makes the most out of a poor script - and at least it stops her acting herself.

Madonna does not appear in the film, which is probably as well given her unhappy recent screen outings. But she is omnipresent behind the camera, as the director, producer and co-writer, and further claims that she was "involved every step of the way from the production design to the editing".

Madonna describes Filth and Wisdom as "essentially my way of putting myself through film school", and it is an extremely canny assessment. The movie is - disappointingly, perhaps - not an outright embarrassment; there are even a couple of intentional laughs in it. It's not an entirely unpromising first effort. But the director would do well to hang on to her day job.

Well, it had to happen. Madonna has been a terrible actor in many, many films and now - fiercely aspirational as ever - she has graduated to being a terrible director.

She has made a movie so incredibly bad that Berlin festival-goers were staggering around yesterday in a state of clinical shock, deathly pale and mewing like maltreated kittens.

Madonna's script is a nightmare of crass and fatuous stereotypes: south Asians, Jews, gays - no-one escapes her lack of insight or common sense. Despite living in Britain for many years, she has only the sketchiest notion of what the place is like.

Madge goes her own way with this scatty story, written largely by herself, about young people dealing with life in London.

The moral of the tale is that you have to go through hard times (filth) before you reach equilibrium (wisdom). But it is punctuated by so much cod philosophising that you wonder whether the film knows what it is talking about at all.

The absence of a decent screenplay doesn't help the energetic actors, and Madonna has far to go before she can breathe the same air as Godard, Pasolini, Fellini and Visconti, whom she insists she admires in a director's statement in which two of the four are mis-spelt.