  The conductance of a quantum wire containing a single magnetic barrier is
studied numerically by means of the recursive Greens function technique. For
sufficiently strong and localized barriers, Fano - type reflection resonances
are observed close to the pinch-off regime. They are attributed to a
magnetoelectric vortex-type quasibound state inside the magnetic barrier that
interferes with an extended mode outside. We furthermore show that disorder can
substantially modify the residual conductance around the pinch-off regime.
