The apparent culprit is /etc/fonts/conf.d/10-hinting-slight.conf from the binary package fontconfig-config (source package fontconfig); Firefox uses the settings from this file instead of using the desktop's settings. Removing that file brings back the correct behavior (hinting matches desktop). I'm not sure whether this is a bug in Firefox or Fontconfig because other programs do not show this behavior.
** Also affects: fontconfig (Ubuntu) Importance: Undecided Status: New -- MASTER - FF 3.5 font hinting does not honour gnome-settings https://bugs.launchpad.net/bugs/379761 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs