Confession: I thought Mandy Moore was sweet and soulful in the drippy A Walk to Remember. And she made an alluring bitch in the sappy Princess Diaries. But the pop diva goes down with the bubbles in this hopelessly shallow soap opera. Moore, 19, plays Halley Martin, a high school cynic who turns against love when her radio-DJ dad (Peter Gallagher) leaves her mom (Allison Janney) for a bimbo. Halley has to deal with the divorce, with her best friend getting pregnant by a jock who dies playing soccer and with falling hard for a teen rebel (Trent Ford) who almost unhooks her bra and then nearly kills her in a car accident. Moore shouldn’t have to deal with the trite script, by Neena Beber, that Clare Kilner directs with moldy, misplaced sincerity. You shouldn’t, either.