Rational torsion in elliptic curves and the cuspidal subgroup

Let A be an elliptic curve over Q of square free conductor N that has a rational torsion point of prime order r such that r does not divide 6N. We show that then r divides the order of the cuspidal subgroup C of J(0)(N). If A is optimal, then viewing A as an abelian subvariety of J(0)(N), our proof shows more precisely that r divides the order of A boolean AND C. Also, under the hypotheses above minus the hypothesis that r does not divide N, we show that for some prime p that divides N, the eigenvalue of the Atkin-Lehner involution W-p acting on the newform associated to A is -1.