  It has been shown that the traditional matching of wavefunctions between
regions of different effective mass (matching {\psi} and
(1/m*)\partial{\psi}/\partialx) is not correct, but that one should match
(1/\surdm*){\psi} and (1/\surdm*)\partial{\psi}/\partialx. It has not been
clear how serious is the error in using the traditional formula. We apply the
two sets of conditions to a simple, but rather general, example and find that
the traditional matching is not even qualitatively correct.
