gtk apps can't see all fonts

My gtk apps cannot see all fonts, anymore. They were able to at some point, but I don't know when that stopped working. The situation now is, that e.g. phoenix offers me only a very limited set of fonts, excluding e.g. ttf fonts. Similar problems in GIMP, Ethereal, etc. I use KDE as the desktop environment. KDE sees the fonts just fine, and I can use them correctly there. Didn't see anything reasonable in /etc/gtk or /etc/gtk-2.0. Any ideas where to start looking? Kostas