Hello Slavcho,
Thank you for contacting Telerik Support.
I confirm that it is an issue with our
PdfFormatProvider when exporting cyrillic text from the
RadRichTextBox.
I have logged it in our Feedback Portal. You can track its progress, subscribe for status changes and add your vote/comment to it on the following link - Feedback Item.
I have also updated your Telerik points.
Currently, the possible workaround that I can suggest is to use the
TxtFormatProvider to export the plain text and then convert the txt file to pdf. You can find more information about converting txt file to pdf on the following link:
http://social.msdn.microsoft.com/Forums/en-US/2cf30017-cd87-4454-8c8f-52a99e76e40c/how-to-convert-text-file-into-pdf-in-c?forum=csharplanguage
I hope this information helps. Should you have further questions, I would be glad to help.
Regards,
Desislava
Telerik