Just for fun I let "Windows Update" install the driver it suggests I use. Problem came back with no LAN recognized. I then downloaded the driver version 6.216 dated 02/26/2009 from
Realtek and the problem is fixed again. I tried it with Green LAN on, and that now works also. I have not lately tried the driver on the cd that came with the motherboard, but it sounds like that one may work also. I find it interesting that Realtek has released several updates to this driver. It is nice to see companies like Realtek (and Gigabyte too) release fixes to problems, rather than pretending that there is no problem. :-)
I hope that helps.