The star of the Old Globe's musical is the new Sheryl and Harvey White Theatre. Based on its inaugural show (state-of-the-art lighting, voms and other entrances, a rounded architectural look), it looks to become the Cassius Carter of the 21st Century. The 1968 musical, however, is as dated as the theater is new: fifty years of marriage in which - except for an infidelity that gets swept under the rug - nice things happen to nice people (and when troubles threaten, the pair recovers, again and again, with a near-miraculous sense of due north). Patrick Page and wife Paige Davis charm as Michael and Agnes, who evolve from virginal newlyweds to septuagenarians in two and a half hours. Director Richard Jay-Alexander and choreographer James Kinney faced a strategic dilemma. I Do! I Do! demands the feel of a dance throughout - on a small stage dominated by a four-post bed. Page and Davis move around the tight space as if the obstacles didn't exist.