Symptom: Ballon from System Tray ping-pongs saying Cable connected -- cable disconnected -- cable connectedwhen it remains attached all the while and other systems have no issues. Nic Card: Broadcom NetXtreme gigabit in default settings. Lan contains 10/100 mb interface (D-Link DSS-5+ - 5 port 10/100 desktop switch ) Solution: use the Broadcom control panel to set the interface back to 10mb/half duplex, no QoS, no power settings. I tried the 10/full duplex and the 100/half duplex as well, but only the 10/mb half duplex would retain a reliable connection. Apparently the Broadcom is drowing the switch to which it is connected. As the entire LAN is 10/100 anyway, this is an acceptable solution. The router is too far away to attempt a direct connection, so a switch/hub is necessary for the physical wiring. Someday we might try another box, vender, or upgrading the whole lan to gigabit.