I also experienced this after a clean install of kubuntu 6.10. The fuzzy fonts appeared in all apps and all fonts. The fix was to change the antialiase hinting from the default of "medium" to "full". Now firefox, and all kubuntu apps are ok for me.
-- Semi-random ugly font rendering in Edgy (no font hinting) https://launchpad.net/bugs/63403 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
