Conrad M. Black, the embattled media baron, has one more overdue bill: he has not made good on a $100,000 pledge to the New York Public Library. Lord Black and his wife, Barbara Amiel Black, were co-chairmen of the Literary Lions benefit dinner on Nov. 3. At that time, he agreed to give the library $100,000, but he has not made the contribution. Instead, Lord Black asked his company, Hollinger International, to make the payment for him. The company refused, according to a person briefed on the situation. Nor did Hollinger take a table at the elegant New York dinner,...