I find why for no work with accent.
includes/upload.php file is check for
-.a-zA-Z0-9 chars. If accent find, is remove.
Find:
$this->file_name = preg_replace("/%20/", "_", $this->file_name);
add after:
$this->file_name = preg_replace("/&Vgrave;/is", "", $this->file_name);
$this->file_name = preg_replace("/&Vacute;/is", "", $this->file_name);
$this->file_name = preg_replace("/&Vcirc;/is", "", $this->file_name);
$this->file_name = preg_replace("/&Vtilde;/is", "", $this->file_name);
$this->file_name = preg_replace("/&Vuml;/is", "", $this->file_name);
Delete image file with accent and try now.