I tried to colpile konversation and ktraynetworker but I got the same error on both:
configure: error: /usr/bin/kde-config --prefix outputed the non existant prefix '' for kdelibs.
This means it has been moved since you installed it.
This won't work. Please recompile kdelibs for the new prefix.
Hmm, I tried to reproduce your problem but everything went fine... I am using Slackware 9.1 with KDE 3.2.2.
That configure error does sound strange, I have never encountered that kind of configure error and I have compiled KDE many times and seen many different kind of errors.
Have you tried to reinstall kdelibs?
What can I do to fix it?
I have Mandrake 10 official.
I've already compiled some QT programs (such as Apollon) and they worked fine, the last thing I did before trying to compile these was to copy (and left them in the original directory) libGL.la and libGL.so to /usr/X11/lib because they weren't there and these programs needed them.
The libraries were located at /usr/lib.
I don't think that moving those libraries caused the error but why not just make a link from /usr/X11/lib to /usr/lib, instead of copying files.
Anyway since I couldn't reproduce that error it might be some Mandrake specific thing.
Hope that you get it fixed.