I have seen a similar issues with this NIC and WHS. I get intermittent connections and never at 1Gig. Does anyone have that realtek Version 5.666.301.2007 driver. It seems to have helped the others with the same problem.
Also i have un-installed and installed various Realtek Windows 2003 drivers so many times, is their anyway to remove the old network connections? I am up to 13!!