# uname -a
Linux bt #3 SMP Mon May 25 18:50:05 EDT 2009 i686 GNU/Linux

The "KDE Help Center" when first started will offer to "Build Search Indexes" for the Help Entries.
This will fail if "htdig" is not installed. BT4 should ship with htdig already working, BT3 had the same issue.

To fix it yourself simply use the "Synaptic Package Manager" to install "htdig" prior to using the Indexer.

This will give these warnings and messages:

"Warning: unknown locale!"
htdig: Errors to take note of:
Unknown host or unable to contact server: help://kregexpeditor/index.docbook Ref: file:///root/.kde3/share/apps/khelpcenter/index/kde_application_manuals.tmp/index.html
Finished successfully.

Now everything works,