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Installed it on 2 Xserves....
GOT AN EXTRA ETHERNET PORT ON BOTH????
When you run ifconfig, the en0 MAC address is duplicated in en2.... (the optional 1Gb ethernet network interface is also installed: en1)
In the GUI the "network' control panel says "new network port found"???

FYI: the Xserves are the "original" Single 1 GHz and the Dual 1 GHz Xserves....
Don't know on a desktop G4 though. Try it later.
 
I also got "A new network port has been detected: Ethernet Adaptor (en1)" on a FW 800 dual 1.42 after I upgraded to 10.2.5 server
 
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