PHP Warning: gethostbyaddr()

[Luca]

I'm getting this warning from Apache:

gethostbyaddr() [<a href='function.gethostbyaddr'>function.gethostbyaddr</a>]: Address is not a valid IPv4 or IPv6 address in /home/domain/public_html/includes/libraries/elxis/defender.class.php on line 82

I have these settings in "Session":
Handler: Database
Lifetime: 15min.
Match IP: Yes
Match browser: No (if Yes, throws an "Unrecoverable Error" when clicking on inbound links)
Match HTTP Referrer: No (if Yes, throws an "Unrecoverable Error" when clicking on inbound links)
Encryption: Yes

I have these settings in "Security":
Security level: Normal
SSL switch: Off
Elxis defender: G+C


Thank you

[datahell]

This is because of a bad IP address.
Do you get this error continiously or only some times? Does this error existing in Elxis error.log too? If yes, can you post the elxis related log entries here?

[Luca]

Thank you @Datahell

I notice that the warning comes when I access the backend. Haven't noticed from other visitors.
Could be the fact that me and the server are on the same IP address? 

[ADD]
Ah, and sorry, no error log entries in Elxis, btw.