elxis 4 error log

[babis1]

i had that error, what does that mean ?
PHP Warning:  gethostbyaddr() [<a href='function.gethostbyaddr'>function.gethostbyaddr</a>]: Address is not a valid IPv4 or IPv6 address in /includes/libraries/elxis/defender.class.php on line 82

[datahell]

This is either server misconfiguration or an evil guest. This may happen if none of the following is available to provide a valid IP address for the guest, which is a little strange.

SERVER['HTTP_CLIENT_IP']
SERVER['HTTP_X_FORWARDED_FOR']
SERVER['REMOTE_ADDR']

If the problem appears again reply below to tell you what to do.