On tonight's 20/20 airing 10 pm/ET on ABC Barbara Walters quizzes CBS Early Show host Bryant Gumbel about quitting morning TV. "It is probably harder to walk away from failure," he admits, "and I guess some people would argue this was! But in this instance, it's just the right thing to do." The divorcé also denies committing adultery with his current fiancée and explains that famed friction with his old Today co-host Katie Couric. "I don't know if I'd call it tension," Gumbel hedges. "Katie and I were never really close."