LoadXML trouble

Hi list! I have a problem with DOMDocument loadXML method. I used Windows to develop my applications, and nothing happens on it when i do something like $xml = new DOMDocument(); $xml->loadXML( $request ); Obviously, request is not empty... But when I have upload this code to production machine ( which runs under Debian ) it doesn't works properly, The DOMDocument Object is empty... Any ideas? Thank you in advance