m0n0wall 1.22 is based on FreeBSD 4.x, so you might want to peruse the
mailing lists/documentation for FreeBSD 4.x a bit and see if there are
any references to installation attempts on igel-232, and verify that
there are drivers for your cards.
When you say "the firewall can't see anything" are you referring to the
console menu where you set up the LAN and WAN connections, or the
firewall setup in the web interface? You should start at the console
and see if the devices are properly seen when the system boots up.