We present some new finite-size results for the Binder cumulant that w
e obtained by means of a transfer-matrix perturbation expansion and by
the cluster Monte Carlo methods - the Swendsen-Wang and Wolff algorit
hms and the largest-cluster method. A finite-size scaling analysis tak
ing into account a correction to scaling locates the critical coupling
at K(c) = 0.221649(4).