  The problem of scattering of neutral fermions in two-dimensional space-time
is approached with a pseudoscalar potential step in the Dirac equation. Some
unexpected aspects of the solutions beyond the absence of Klein\'{}s paradox
are presented. An apparent paradox concerning the uncertainty principle is
solved by introducing the concept of effective Compton wavelength. Added
plausibility for the existence of bound-state solutions in a pseudoscalar
double-step potential found in a recent Letter is given.
