Kozma, hello. This server is running PHP in safe mode which is depreciated since 5.3.0 (See here
http://php.net/manual/en/features.safe-mode.php ). This safe mode adds the restrictions you see on your screen. It COULD work under safe mode only if the host was to do a good job at setting up the right directories path. At this point, if you have no control on the PHP setup, or the .ini, I would recommend going to another host.
Best regards.