I fixed this today, after days of seeing threads about Helvetical and Arial… thought the fonts being displayed wrong were never either of these. I resetting everything, including "Restore Standard Fonts…".
The I found an ALIAS called "Arial Unicode.ttf" in this location:
/Library/Fonts/Arial Unicode.ttf
This file points to the original font ( /System/Library/Fonts/Supplemental ), which needs to stay the same. But removing the ALIAS fixed the problem! :)
As it's already in the System fonts i see no reason for there to be an alias there!