Panel spacer missing in 10.10/KDE 4.5.5

[Jose Gomez-Dans]

Hi,

I wanted to insert a panel spacer plasmoid in a panel (click the
panel's cashew -> Add Spacer), and all I get is a red button telling
me of "unknown widget". When the mouse hovers over, it says: "could
not find requested component: panelspacer_internal"

Does anyone have any clues whether this is a KDE or a Kubuntu bug? Or
am I missing something really obvious? there seems to be something in
/usr/lib: /usr/lib/kde4/plasma_applet_panelspacer_internal.so, but I
don't know whether it's relevant or not.

Thanks!
Jose