Many of our themes are using cufon font replacement method.
Depending on font we’re using in theme, titles may not working as it should. For example, some fonts just dont support japanese, chinese letters, cyrillic letters etc. If you have this kind of a problems, and you want to fix this, there’s no other way then to remove cufon! To do this, you must open header.php and find Cufon.replace function. You need to delete this whole function, and you may also want to delete calls for cufon-yui.js file and call for cufonized font (always bellow cufon-yui.js in header.php).
So, delete this 3 things, and it will work good. You may need to adopt css little bit, but thats the only way.