When you say:
when selecting a file with a filename that contains accented "z" it'll throw a "List Index Out Of Bounds (0).
-can you be more specific? I mean, just by selecting such file(name) inside GUI, this can't happen... can you describe what you try to do when this message appears?
I ask, because I live in East Eurpoean country, where accented characters are used (not all, though) and never had problems when such characters are used in filenames.