There is an error in the manpage of xfce4-screenshooter 1.8.0: 'man xfce4-screenshooter' says: "-m, --mouse Do not display the mouse on the screenshot" 'xfce4-screenshooter -h' says, "-m, --mouse Display the mouse on the screenshot" help is right, manpage is wrong.
Sorry, this was already fixed in http://git.xfce.org/apps/xfce4-screenshooter/commit/?id=5dbf2373