Comment 6 for bug 1051575

clicking on corresponding icon gives nothing.
The reason is printed into console:
systemsettings: Unexpected argument '%i'.
systemsettings: Use --help to get a list of available command line options.

systemsettings works just fine when executed manually, so xfce4-settings should call it with correct options. Also if call fails for whatever reason user should be presented with error message in gui instead of silent failure.