I am actually wondering if the problem you are having is caused by the font used. It may just miss the unicode characters you need.
You have 2 available fonts: the default and arial.ttf. You may want to try and add a TrueType Font that has all the unicode characters needed.
Additional TrueType fonts can be placed into the folder
Simplify Your Web is not affiliated with or endorsed by The Joomla! Project™ or Open Source Matters. The Joomla!® name and logo is used under a limited license granted by Open Source Matters the trademark holder in the United States and other countries.