Have to reset ethernet adapter in Vista for Internet access

Our wired network connection frequently and intermittently goes to local access only and requires a reset of the adapter in the networking utility of Vista Home Premium 64. There seems to be no rhyme or reason as to why or when it drops. Sometimes it will stay up for hours and sometimes it will drop every few minutes.

Computer is Acer Aspire x1200 with 4GB RAM. OS is Vista Home Premium 64, SP1. Network connection is through a Netgear WGR614 wireless router with 4-port ethernet switch.

A Toshiba laptop and Compaq desktop running WiFi have no connection problems. Dell and Gateway XP towers on ethernet are also OK.

Acer published a BIOS update to address a problem with the adapter shutting down, but I've seen no mention of the reduced connectivity problem.

Check the power management settings in device manager.

Try disabling 'Allow the computer to turn off this device to save power'

Power management is already disabled. Besides, the device isn't being turned off. Local access is still available. It just loses the ability to see the internet. Vista's diagnostic utility suggests a device reset, which always beings it back.