This question has been answered several times this week on the forums:
You should download and run the FontFixer on the same page as the upgrade.
http://www.accordanc..._installers.php
You may need to run it twice and to restart the Mac, in the case of Snow Leopard.
If the FontFixer does not correct the problem, I recommend opening FontBook and looking at Helena per the instructions in the Accordance Fonts PDF. It is probably accessing either old copies of Helena or bitmaps.