Karen and Richard Carpenter visit the Nixon White House.National Lampoon years popularized the slogan, "That's not funny, that's sick." Surely, the folks there would therefore see the humor in a novel that centers on a love story with the late Karen Carpenter.Many readers will have to ask their parents who Carpenter is, but the quick answer is she was the singer and drummer with the hugely popular mild '70s pop duo The Carpenters, which was rounded out by her pianist brother Richard Carpenter. T