I wish I could get fonts to work properly, but perhaps I can help you. My understanding is that recent KDE's (i.e., 3) use fontconfig for a lot of their font functionality. So if you want it to work right, you have to enter the proper fonts in /etc/fonts/local.conf. You may also need to run fc-cache -fv. KDE mostly relies on Qt; Qt relies on fontconfig. KDE 2 used an earlier version of these same things, controlled, I believe, through /etc/X11/XftConfig.