While trying to retrieve the URL: http://www.gravatar.com/avatar.php?
The following error was encountered:
Unable to determine IP address from host name for www.gravatar.com
The dnsserver returned:
Refused: The name server refuses to perform the specified operation.
This means that:
The cache was not able to resolve the hostname presented in the URL. Check if the address is correct.
Your cache administrator is webmaster.