eth0 does not seem to be present

[Michael Koppelman]

I just installed YDL 4.0.1 on a Rev A iMac. The install went fine. When 
I booted after install there was no network interface on the ifconfig 
list, just the loopback interfaces. I used the Network control panel 
dealie and there was a device listed in the Hardware tab called "GMAC 
(Sun GEM)" with status "ok". There was no device in the device tab. I 
added an Ethernet device to the appropriate hardware device, saved and 
clicked activate and I got the dreaded:

"sungem device eth0 does not seem to be present"

I have searched the web and the mail lists and could find no advice on 
how to proceed. According to the YDL site the network card in this 
computer is supported. I have no idea how to make the eth0 device show 
up in ifconfig. The Network system setting application seems to think 
it is there and "ok". I have tried editing, adding, deleting hardware 
and devices and restarting the network and rebooting and such to no 
avail.

What to do?

Thanks!
Michael Koppelman