It's been a while since I manually configured a net card, It should have been
seen on bootup and ashed to be configured.

Are the 2 cards the same brand? I have had good luck with Dlink DFE 530 and
Linksys LN 100 (I think).

A suggestion, as root do lspci and see if there is a listing for both cards
in the list of devices printed out, if it rolls by too fast do lspci | more.