I figured a card this old would work but it's not. I looked through the startup messages and noticed this error: "MII without any PHY!" The card is a version 4.1 and it works fine under Linux. M0n0wall detects the other card (an Intel) just fine.
I've used these before without any issues, but I can say that a IRQ conflict may exist as sometimes I've seen this happen with these cards and other brand cards (like Intel, Netgear, etc.)
First try disabling Plug n' Play in BIOS with the reset PCI configuration option to see if the IRQ mess can get sorted out before m0n0wall starts.
If that still doesn't work, try m0n0wall 1.3 release as that certainly has support for the card listed.