Recently, Glassmeier (1983,1984) has discussed the consequences of nonuniform ionospheric conductivities on resonant Pc 4--5 electric field structure. One result of his work was the suggestion that ionospheric conductivity structure may have caused the pulsation double-resonance event described by Nielsen and Allan (1983) in which a monochromatic pulsation was seen to resonate simultaneously at two different latitudes. Examination of this suggestion leads to the conclusion that although spatial conductivity variation may have contributed to the creation of the double resonance, it is unlikely to have been the sole cause.