Molly Sims and Kathy Najimy were two stars who couldn’t find Donna and Gabby Karan’s East Hampton compound over the weekend for a premiere of “The Perks of Being a Wallflower.” “They arrived an hour late after going in circles trying to find Donna’s home,” said a spy of the hidden address. Barbra Streisand and James Brolin were seen slipping into the Cinema Society event, attended by Katie Couric, Sir Paul McCartney, Barry Manilow and Lou Reed.