MythTV frontends connect to the database, and queries it for the location of the backend.
LinHES makes a few assumptions about it's setup. One of those is that a LinHES backend will be used with a LinHES frontend. As a result it assumes that the database username/password is the LinHES default. My guess is that the username/password for your database is different from the mythtv default. On the linhes machine look at /usr/share/mythtv/config.xml (/home/mythtv/.mythtv/config.xml should be a symlink) and make sure those values are correct for your setup.
Additionally linhes stores some of it's host specific values in the database, so those will need to be reloaded as well.
This command, run on the linhes machine, should take care of that for you.
Code:
myth_settings_wrapper.sh -c restore -t syssettings
Regarding the name, if it's a static ip then then hostname must also be given.
The hostname is typically only handed out by the DHCP server if it's also assigning an ip address.