We reexamine a model for spontaneousCP violation and particle-antiparticle asymmetry in which two spinor fields are coupled to two scalar fields through Yukawa couplings. The model has a gauge symmetry and a Higgs potential which, in tree approximation, has a minimum when the vacuum expectation values of the two scalar fields are identical in magnitude but differ by a phase. We show that when one-loop contributions to the effective potential are included, a new nonperturbative vacuum state can appear at a new minimum in which even the magnitudes of the vacuum expectation values of the two scalar fields differ. This second nonperturbative vacuum state manifests spontaneousCP violation due to radiative corrections of the effective potential, a result manifestly different from the consequences of using the tree approximation to the effective potential. In both ground states the model develops two different kinds of domains, in which the particle masses are identical, but the coupling constants in the effective Lagrangians differ. Even when such violations do occur, baryonantibaryon number asymmetries still will not develop unless baryon number violation is initially built into the model. We also note that decay rates for unstable particles are different in the two kinds of domains, even though these total decay rates must be identical for particles and antiparticles in any one domain.