[kde-linux] Digikam and Gwenview cannot find kipi plugins

[Bogus Zaba]

Slackware 13.37, KDE 4.5.5 (as supplied by Slackware).

I have both Digikam (1.9) and kipi-plugins (1.9) installed from 
Slackware packages. Neither digikam nor gwenview can see any plugins. 
Tried re-installing both digikam and kipi-plugins, but I still have the 
same outcome - no kipi-plugins available.

The digikam splash screen provides a few progress messages among which 
is "loading kipi plugins", but nothing seems to result from this.

One clue might be this output which comes from running gwenview at the 
command line:

"
gwenview(14654)/kdecore (trader) KServiceTypeTrader::defaultOffers: 
KServiceTypeTrader: serviceType "KIPI/Plugin" not found
"

This suggests that kipi-plugins should have registered itself as a KDE4 
service (presumably during installation of kipi-plugins). There may be 
something in my KDE4 setup which is preventing this.

Any clues as to how I may be able to correct this?

Thanks