1. Check the GUI network interface configurator to be sure all settings are correct. Note that hostname is the machine name, not the FQDN.
2. Check the files in /etc/sysconfig/networking/profiles/default... this directory houses all your networking-related files relevant to the interfaces... check your hosts, resolve.conf, network, and ifcfg-XXX files to be sure they are correct. Also, double-check the ifcfg-XXX files to be sure the netmask is correct, FC10 has a bug when using the GUI that inserts the gateway in the netmask field.
3. Run the commands "chkconfig NetworkManager off" and "chkconfig network on" to disable Network Manager and assure that default networking is activated in all runtime modes. This was key to having interfaces come up as Network Manager is a buggy piece of garbage when using static IP.
Make sure your ifcfg files look something like this...