KATHERINE Heigl continues her pitch as America s new sweetheart with another polished performance in Greg Berlanti's misfiring comedy LIFE AS WE KNOW IT (12A) about an unlikely couple brought together in mourning. Following on from winning turns in

KATHERINE Heigl continues her pitch as America's new sweetheart with another polished performance in Greg Berlanti's misfiring comedy LIFE AS WE KNOW IT (12A) about an unlikely couple brought together in mourning.

Following on from winning turns in Knocked Up and 27 Dresses, the statuesque actress brings out the best in usually leaden co-star Josh Duhamel, wringing a few decent laughs from a linear screenplay that doesn't once defy our expectations.

Director Greg Berlanti delivers these lighter scenes with assurance, including a disastrous first date that opens the film, but the abrupt shifts in tone are uncomfortable, almost celebrating the shocking demise of two pivotal characters.

Holly Berenson (Katherine Heigl) is the culinary genius behind a burgeoning catering business while Eric Messer (Josh Duhamel) is a fast-rising director for a sports television channel.

While Holly and Eric might not like each other very much, they put their differences to one side to play doting godparents to Sophie, the baby daughter of their mutual best friends Peter (Hayes MacArthur) and Alison (Christina Hendricks).

Then out of the blue, fate deals the friends a devastating and cruel blow.

Peter and Alison are killed and in their will, the couple name their best friends as legal guardians of Sophie.

Holly and Eric are horrified but faced with the choice of putting the baby girl into care, the sworn enemies agree to move into Peter and Alison's home to become surrogate parents.

Life as We Know It ticks off all the clich�s including a clumsy first attempt at changing a nappy that leaves Heigl's spirited heroine with a little more than egg on her face.

Duhamel is easy on the eye and makes an attractive paramour but on screen chemistry with Heigl is lukewarm. Rating: 5/10