First, choose someone NIC from existing list (doesn't matter which one).
Than, continue installation until it completes.
After system reboot, press Alt-F2 and login as root.
Execute command:
/sbin/e-smith/config set EthernetDriver1 3C509
if you have second NIC, than enter:
/sbin/e-smith/config set EthernetDriver2 3C509
Finally, go back to e-smith main screen with Alt-F1 and choose the secind option from the menu "Configure this server and gateway". At this point e-smith will offer your NICs as default, simply confirm them.
Hope, this will help you.