problems with flashdta with diacritics

[eluser]metelesku33[/eluser]
i got troubles to show some flash messages with diacritics

i used lang files encoded in utf-8 and loaded messages with $this->lang->line

i set flashdata with $this->session->set_flashdata('info', $info);

but when in $info is like "Váš účet a email boli úspešne overené. Prosím prihláste sa!"
the message is not displayed via echo $this->session->flashdata('info');

the problem charecter is "č" as I discovered

some text with diacritics are displayed OK