Routers ignore ReadyNAS MAC address - 00:00:00:00:00:00 ??

We're upgrading our infrastructure and we have a ReadyNAS Ultra 4 that would talk to our old router but not the new one. What's odd is that both MAC addresses are all zeroes both in RAIDar and RAIDiator even though the Host Name has the last part of the original MAC address in it.

Changing the settings to DHCP makes the ReadyNAS display 192.168.168.168, but it's unreachable. If I have it connected to both networks, RAIDiator reports an unsuccessful DHCP request popup. A static IP is also unreachable. I've tried changing the router to 192.168.168.1 and issue IPs from there, but no luck. On the router side, there are no DHCPREQUESTs in the log.

Is there a way to change, reset, or otherwise modify the MAC address from all zeros?

Here's a thread about the MAC address: http://www.readynas.com/forum/viewtopic.php?f=64&t=56786
...and here's a potentially related thread about the DHCP issue: http://www.readynas.com/forum/viewtopic.php?f=7&t=54307

Obviously I've tried updating the OS (from 4.2.16 to 4.2.22), rebooting to OS reinstall, and changing every setting for eth0 and eth1. Setting 00:00:00:00:00:00 to a static IP on the router didn't work either.