Hi,
There's an icon file missing in passwdmaker-0.7.xpi for Linux. It should be in
%Profile%/extensions/{5872365E-67D1-4AFD-9480-FD293BEBD20D}/defaults/passwordmakerdlg.xpm
and gets copied to (if it's not already there)
%MozDir%/chrome/icons/default/passwordmakerdlg.xpm
where %MozDir% is your Mozilla/Firefox installation directory, and %Profile% is your profile directory.
This file is the icon the passwordmaker dialog (a ring). On windows, it's a .ico file -- which is in the passwdmaker-0.7.xpi. I forgot to put an xpm version there. You can safely ignore the warning, or give me a day or so to make the .XPM. I'll post it here and you can manually copy it to %Profile%/extensions/{5872365E-67D1-4AFD-9480-FD293BEBD20D}/defaults/passwordmakerdlg.xpm. That will fix the problem.
Sorry for the inconvenience,
Eric