  Systematic trends of nonuniversal behavior of electron transmission phases
through a quantum dot, with no phase lapse for the transition N=1 -> N=2 and a
lapse of pi for the N=2 -> N=3 transition, are predicted, in agreement with
experiments, from many-body transport calculations involving exact
diagonalization of the dot Hamiltonian. The results favor shape anisotropy of
the dot and strong e-e repulsion with consequent electron localization, showing
dependence on spin configurations and the participation of excited doorway
transmission channels.
