I managed to fix that problem. You just need to save the iReport as a .rtf file while using the Central European encoding (CP 1250), then open it with Microsoft Word 2007 and then use the Save As option to save the file as .pdf. To do that you need to install a small add-in for Word 2007 from Microsoft website: http://www.microsoft.com/en-us/download/details.aspx?id=7