  We numerically investigate the decay, via parametric resonance, of the
inflaton with an m^2 phi^2 potential into a scalar matter field with a symmetry
breaking potential. We consider the case where symmetry breaking takes place
during inflation. We show that when expansion is not taken into account
symmetry restoration and non-thermal defect production during reheating is
possible. However in an expanding universe the fields do not spend sufficient
time in the instability bands; thus symmetry restoration and subsequent domain
wall production do not occur.
