I experience the same problem with Kubuntu Feisty after upgrade from Edgy. Some of the Polish characters are visible as rectangles just like on the screenshot from Breezy. That's with the default fonts: Serif and Sans Serif and many others - I had to change fonts to Lucida Sans or some others, which do have all Polish characters.
-- Polish fonts missing some characters https://launchpad.net/bugs/20921 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
