> For instance, konqueror switches to some unreadable font
> (probably one of the alias* fonts) during loading of
> http://www.kde.org/. It starts displaying the page with a
> suitable font but then somewhere in the middle of the load
> process, it switches fonts. If have searched the ~/.kde
> for an "alias*" font entry but got no hits.

I think this is not the NetBSD specific problem, so it is good to
repeat you question on mailling list of XFree86.org.
(maybe also report your crash about xtt module)

> But after removing the fonts.alias file, the problem went away.
> Nevertheless, I believe that there is something wrong with
> mkttfdir or the X server (or KDE!...).
> 
> Thanks for your help!

You're welcome. I also have to learn more things. :)

-rxg