Filter spurious/duplicate accessory events (Fixes: NB 147573).
Filter spurious/duplicate accessory events (Fixes: NB 147573).

maemo-foss/maemo-multimedia-ohm-plugins-misc,tswindell/ohm-plugins-misc,maemo-foss/maemo-multimedia-ohm-plugins-misc,jusa/ohm-plugins-misc,jusa/ohm-plugins-misc,jusa/ohm-plugins-misc,jusa/ohm-plugins-misc,tswindell/ohm-plugins-misc,tswindell/ohm-plugins-misc,maemo-foss/maemo-multimedia-ohm-plugins-misc