I do notice one thing from the original post: the user seems to be using Windows, and PHP5 (and older) do not support multi-byte (e.g. UTF8, UTF16, etc) filesystem operations (open, read, etc) under Windows.
by the PHP team:
This is not a bug but missing feature. And this missing feature will be in PHP 6.
Please confirm you're also using PHP under Windows? If so you may be out of luck until PHP6.