non english characters

You'll have to edit includes/config_vbseo.php and in the bottom of the file you'll see where to replace the characters.

Hello,

these character replacements are defined by manually editing of config_vbseo.php file. Look for $vbseo_custom_char_replacement definition near the end of file.
Example:
$vbseo_custom_char_replacement = array(
'Č' => 'c',
'Ğ' => 'g',
);

Yes, it should be working fine - just enter the replacements as described.