two nics, one dhcp server

[dave]

Hello,
    I've got a machine that i need to give two separate addresses to using
two nics, both of which are 3c905's, working fine under 5.2.1. I've got
lines in rc.conf set so they both get their addresses via dhcp, however this
isn't working. Having both cards in the box neither gets an IP, singley they
work fine. Cabling is working, and i'm out of ideas as to what to try.
    Is this configuration possible? Any help appreciated.
Thanks.
Dave.