By Owen Gleiberman
Updated February 28, 2007 at 05:00 AM EST

Heather Graham, with her quick, laughing charm and her sunstruck beauty, has mismanaged her career as badly as any actress, but doesn’t she at least deserve a tartly written commercial chick flick? Instead, she’s stuck in fodder like Gray Matters, a tee-hee precious Omigod-I’m-a-lesbian! comedy. She and Tom Cavanagh play brother and sister, who behave like platonic boyfriend and girlfriend — until they both fall for hot zoologist Bridget Moynahan. Graham makes the coming-out dithering bearable, but not before she has jumped through hoops of contrivance. C-