I don't understand why survey template (when I generate pdf document from survey) pdf does not recognize non ascii symbols. It shows black squares in places of those symbols. The strange thing is, it only happens on one server. On other servers it shows normally. Don't understand what that server is missing, because survey module is the same. Any suggestions what could be the problem?

P.S. if I try o print for example invoice in different language (that has non ascii symbols), everything works normally in that server. There is only problem with survey.