Thank you sbillad, but it is just a half solution to not use these letters in filenames. remember 1.1.5 works correctly with it.
Still can't use these letters in description, title... But these letters are shows correctly in tag.
The tags are in another database? no, so we are at the first question again. By the way, the site is utf-8 too, so it must be good.
Thank you,
Slidey