I'm actually having the same problem with the same motherboard. It is currently flashed to the newest revision, I'm running a 64-bit windows 7 with a phenom quad, 4gbs of 800mhz RAM, and an aftermarket cooler.
For giggles and grins, I re-imaged the drive, reset the BIOS with the jumper, I even pulled out the RAM, the BIOS battery, and the power cord but still no Internet.
In my device manager, it doesn't even have a Ethernet adapter in there. Just my Bluetooth adapter.
For another giggles and grins, I even pulled out an older adapter that I know works, and still had the same problem (it was a realtek card as well)