Dan,
Thanks for the suggestion.
The BIOS LAN power setting selected is [stay off].
The OS is Win7 x64.
As I indicated in the original post the LAN disconnect occurs with the latest Driver Package.
However, the actual 82579V network adapter Driver Version 12.2.45.0 is the same for both ProWin7_64_17 and ProWin7_64_18 [PRO Network Connection for Windows 7] driver upgrades.