Disabling the RAID made no difference.
Also, I was too optimistic with my analysis. Even though the system came up fine after installing the NIC cards, as soon as I started configuring it via the web interface, things got wacky. After each change I would lose access to the web interface. I could still ping the firewall and the console was still OK. But, even restarting the webconfigurator from the console would not bring access to the web gui back. I had to fully reboot the server.
I think I'll start up a new thread that references this thread. Since this one is getting long winded, I want to post a summary of my issues and what my options are moving forward.