On page 5, column 2, line 1: It should read "\log^5(N_T Q)" instead of "\log(N_T Q / \max_i D_i)" On page 5, column 2, second-last line of Theorem 4: It should read "O(N_T Q)^{-O(1)}" instead of "O(N_T L)^{-O(1)}"