While doing some poking around to put together the most practical way to package the M$ updates for a s2k8r2 Vail an off-line install & storage, I found the URL for an updated March 2013 LAN driver.
This was using an ex49x so I'm certain it wont work on a ex47x. Not sure yet if it's an x64 only driver either.
I don't have a ex48x to test with, but I happen to have a v1 OS on a spare drive to test it on my ex49x. Will post results of running it on an x86 system this week.
http://download.windowsupdate.com/msdownload/update/driver/drvs/2013/03/20315222_fdfd43a395bced94c6c56296c3d41f983261be96.cab