William:
I should also mention to check the contents of /etc/hosts. Some distributions put the FQDN as the localhost IP, like so
127.0.0.1 host.domain.example.com
This can interfere with DNS based name resolution in strange ways. It can also cause problems if a later line in /etc/hosts defines the FQDN differently. Many operations will appear to behave correctly in such circumstances, while others will mysteriously fail or behave in unexpected ways. If your server has an active network connection with an assigned IP address, the two will clash and cause some trouble. If the entry is present, I recommend removing it and retrying any tests and operations.
Best regards,
Bryce Ryan