I can confirm this problem against Ubuntu Feisty Herd 2 with a Radeon Mobility M6.
Unfortunately the patch mentioned is taken from two years ago, I think it may no longer be valid. -- Font rendering glitches with radeon, known bug, patch exists https://launchpad.net/bugs/62537 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
