  A dual pair of supersymmetric string theories that involves an asymmetric
orbifold and an orientifold of Type II is considered. The D-branes of the
orbifold theory (that were recently determined by Gutperle) are all non-BPS and
do not carry any conserved gauge charges. It is shown that they carry
non-trivial K-theory charges, and that they can be understood in terms of
branes wrapping certain homology classes of the M-theory compactification.
Using the adiabatic argument, dual partners of some of these non-BPS D-branes
are proposed. The relations between these dual states are found to be in
agreement with the M-theory description of the D-branes.
