Just an absolute newbie running Inkscape 0.48.2 in a well working,
really beautiful, vintage declared but loved computer (2.1 GHz
PowerPC G5 & Mac OS X.5.8).
To get Previews from the Open Clip Art Library*, it is needed to be
registered at the openclipart.org site and fill up the user account
data in the Inkscape Preferences**?
* File > Import from Open Clip…
** Import/Export > Open Clip Art Library Username & Password.
Eneko Gotzon Ares