"?" problem in post titles on home page

I don’t know, may be there is character limitation problem?

see if there is a problem with charset encoding

define('DB_CHARSET', 'utf8');
define('DB_COLLATE', '');

So?

My DB collation is utf8 unicode
So I don’t see any problem with charset

//define(‘DB_CHARSET’, ‘utf8′);
//define(‘DB_COLLATE’, ”);

doesn’t work.