There are a lot of people that don’t understand how to configure /etc/hosts. There are services that complains about that, for example: Zimbra, Apache, Squid, etc. The right syntax of every entry in /etc/hosts file MUST be:
188.8.131.52 myserver.example.com myserver
If you write that wrong, there are some functions of libc that don’t work properly because they are expecting “
To be sure that you /etc/hosts is right, run hostname -f and hostname. They should return the FQDN and the hostname respectively.
One last thing. The hostname of your server is the short name, not the FQDN!