Quote Originally Posted by cl_out
Last time I had font problems in KDE after trying to add some fonts from my Windows installation, I logged out of KDE, wiped the font cache and related files in my home directory (<span style="font-family: monospace;">~/.font*</span>), and logged back in to fix it. You might want to back up the cache rather than wipe in your case though

I tried renaming the files there (fonts.cache-1, fonts.dir) for backups, then restarted, but nothing changed. It only spawned a new fonts.dir file.