The Black Dahlia marks something of a return to form for Brian De Palma, one of the few genuine stylists left in mainstream American cinema . That this muscular, handsomely mounted detective story, set in 1940s Los Angeles, ultimately disappoints is down to poor casting, and the fact that it follows the adaptation of another James Ellroy novel, LA Confidential, which simply raised the bar too high .
The story is a spin on a real unsolved murder from 1947; aspiring actress Betty Short was cut in half and dumped in a vacant lot. As detectives Bucky Bleichert (Josh Hartnett) and Lee Blanchard (Aaron Eckhart) investigate the case, they delve into an LA underground that is populated by corrupt politicians, seedy film-makers and the sad wannabes on which they prey.

Like LA Confidential, and Chinatown before that, this mines the edgy energy of a city still establishing itself. De Palma’s natural bravura is evident, especially in the opening street riot, and there are a couple of the director’s trademark set-pieces, the camera flitting about like a character who doesn’t know where to look. The film’s standout scene – involving two murders, a cross-dresser and a blade in a hotel lobby – takes us right back to Dressed To Kill, via The Untouchables.

Around these highlights, though, the film veers between humdrum and hysterical, without the anchor of a really good lead. Eckhart has the right worn-in quality for this kind of film, but he’s marginalised as his girl (Scarlett Johansson) eyes up his partner; and both Hartnett and Johansson are simply too callow for the material. Hilary Swank provides the one class act, as a hilariously eccentric heiress.

Based on another true mystery, as experienced and distilled in a novel by Armistead Maupin, The Night Listener has a creepy premise made underwhelming by poor execution. It may still, though, engender an unhealthy distrust in telephones, children and blind people.

Robin Williams is a maudlin Maupin surrogate as Gabriel Noone, a radio personality who becomes phone pals with Pete, a 14-year-old who has turned a sad life of abuse and ill health into a compelling book. Noone, who has just been left by his lover, finds comfort in the odd relationship, until he begins to doubt if the boy, whom he has never met, actually exists. That Pete might be a fiction created by his supposed stepmother (Toni Collette) is the discomforting idea on the table.

In keeping with its title, and with just about any comedy starring Will Ferrell, Talladega Nights: The Ballad Of Ricky Bobby is pathetically over-the-top. As co-writers, Ferrell and director Adam McKay just don’t know how to let a joke end – so that even the good ones become numbing. There is one saving grace here: as Bobby’s French rival, Sacha Baron-Cohen creates a comic villain that touches the greatness of Peter Sellers. He’s almost worth the pain.

Unconscious is a delightfully bonkers, and deceptively smart comedy involving sleuthing, romance and psychoanalysis in Barcelona in 1913. Leonor Watling and Luis Tosar make an engaging double act, as the mismatched pair falling in love while in search of her Freudian husband.

An Inconvenient Truth, Al Gore’s fêted documentary on global warming, destroys the idea that a lecture on film should be boring – it is far more riveting than the format suggests, adds Edd McCracken. It annihilates the perception that Gore himself is a charisma vacuum – Americans should weep that this articulate, witty and passionate man was never President. It goes for the jugular of big business and its pernicious influence. And most importantly it attacks our laissez-faire attitude towards the environment.

In Gore’s sparky lecture, we learn that mankind has wreaked more havoc than any Bond villain could imagine. Ice-caps disappearing? Check. Slowing down the gulf stream? Check. Creating superhurricanes? Check. We’ve done it all. But if mankind is the arch-villain in Gore’s film, we’re also the possible hero. The closing 10 minutes are the former vice-president’s Gettysburg Address. He succinctly calls us to action, stressing that it’s not too late, that we can do something. Where a Michael Moore documentary makes the viewer feel angry but essentially helpless, An Inconvenient Truth skilfully leaves you scared, angry but ultimately motivated. It could save the world.