Comment 5 for bug 745625

The pdf_tex file uses utf-8 encoding, which will seem odd when viewed as any 8-bit fixed-width encoding. Errors with pdflatex are quite unexpected, though. If the .tex file is properly set up for Finnish, pdflatex should not error on those characters, though it may produce odd-looking results. See http://en.wikibooks.org/wiki/LaTeX/Internationalization#Finnish

As a workaround, you can either convert the pdf_tex file from utf-8 to latin-1 / windows-1252 with a text editor (AFAIK even notepad can do that) or use utf-8 in your whole document.