You can see what I mean here: http://img500.imageshack.us/my.php?image=debianfontcorruption4vr.png
I'm running unstable. It happens only in GTK2 apps (not GTK1, not Qt), with the notable exception of Firefox (1.5), although I was under the impression that one is also based on GTK2; however, neither pages nor menus/dialogs are affected in Firefox. I tried several DPI, same thing. The fonts are good, since I use the almost exact same setup on another box (nearly identical xorg.conf and font configuration), and no problem there. I realise there are a LOT of things that could cause this: xorg, fontconfig, xft, freetype, gtk or gnome libs... I'm just hoping somebody has an idea of what I could do or test to narrow it down.
