Twenty-seven years after Robert De Niro asked Jane Rosenthal to leave Los Angeles and her career as a rising Disney exec to come work for him, the partnership still is going strong. There is only a wall separating their offices on the top floor of the eight-story Tribeca Film Center. De Niro's workspace ? which teems with mementos from nearly five decades of filmmaking ? is where he goes to make calls and, he jokes with Rosenthal, struggle with the Internet: "I don't really go to websites other than The New York Times on Sunday. She'll send me websites to go to." Responds Rosenthal, 58: "Then he'll say, 'How do I open this?' "??