Cairo Dock only showing on one desktop

OpenSUSE 13.2 KDE

Information for package cairo-dock:
Repository: @System
Name: cairo-dock
Version: 3.4.0-1.1
Arch: x86_64
Vendor: obs://
Installed: Yes
Status: up-to-date
Installed Size: 1.5 MiB

I just noticed that the dock is only shown in the first desktop. If I switch to another one, there is no dock. This never happened to me on other distros, but I only used Gnome before, so I don’t know whether it’s something about KDE or OpenSUSE. Navigating through the settings I don’t see anything relevant.

What could I do?

it turned out to be KDE’s fault.

kstart --alldesktops /usr/bin/cairo-dock