Gigabit Ethernet G4s and Cisco Ethernet switch problem

Steven Hayes has had problems using the Gigabit Ethernet connection on the new Power Mac G4s with a Cisco Catalyst 4006 switch. Cisco informed him that the switch is not supported for the new G4s: We have experienced frustrating dropping in and out of network services and printers within the Chooser. Cisco have advised that they do not support the new 10/100/1000 Ethernet G4's because they do not conform (in their opinion) to 10/100 and/or 1000Mbit over copper. They advised that Apple must use some sort of "software tricks" to enable compatibility with the 10/100 standard as well as 1000Mbit standard. According to Cisco, the current networking standard they support and acknowledge is either 10/100 OR 1000Mbit. Update: Patrick Ellis also had network drops with his Gigabit Ethernet Power Mac G4, connected to a Cisco 2900 XL Switch. He offers this potential solution: I found an old copy of Apple's unsupported Duplexer Tool from last year and dropped the Duplexer 100 full Extension into the System Folder. Except for a slight delay in the network connecting up at startup, all has worked fine since." Update: A MacNN article describes what appears to be this same issue and contends that is extends beyond Cisco switches. (Thanks, Frank Piccolo.)