I get this error now:
forcedeth device eth1 does not seem to be present, delaying initialization.
The network configuration says eth0 is using forcedeth and eth1 is using nVidia MCP55 Ethernet. Both should be using forcedeth. There's also a problem with eth1 not reporting a MAC address. I'm sure that's part of the problem.
I'm going to try to install another NIC (actually right now I only have a USB ethernet adapter) to see if I can access the microscope controller.
I'm close now I think.