When setting up the X server and the  proprietary ndivia driver, as
described here (https://wiki.gentoo.org/wiki/NVidia/nvidia-drivers), I
emerged nvidia-settings, as suggested in the wiki article, The drivers
can be installed with the *gtk* USE flag set in /etc/portage/make.conf.
This will install *media-video/nvidia-settings*, a handy graphical tool
for monitoring and configuring several aspects of your nVidia card.

The version of the nvidia driver and nvidia settings I emerged is:
box0=; equery list '*'|grep nvidia-driver
x11-drivers/nvidia-drivers-319.32

I then emerged xfce4 as well as the xfce4-sensors-plugin (box0=; equery
list '*'|grep xfce4-sensors-plugin
xfce-extra/xfce4-sensors-plugin-1.2.5), which pulled in nvidia-settings
of an older version:
box0=; equery list '*'|grep nvidia-settings
media-video/nvidia-settings-304.60

I had a look at the xfce4-sensors-plugin ebuild, and found
nvidia-settings listed as a dependency, with no version specified.

RDEPEND=">=x11-libs/gtk+-2.14:2
    >=xfce-base/libxfce4ui-4.8
    >=xfce-base/xfce4-panel-4.8
    hddtemp? ( app-admin/hddtemp net-analyzer/gnu-netcat )
    libnotify? ( >=x11-libs/libnotify-0.7 )
    lm_sensors? ( >=sys-apps/lm_sensors-3.1.0 )
    video_cards_nvidia? ( media-video/nvidia-settings )"

I now seem to have both versions of nvidia-settings installed.

How do I fix that please?

Thanks.

Alexander Kapshuk.