AMD has released new versions of the 64bit processors drivers (for x64, server 2003 and xp):
http://www.amd.com/us-en/Processors/Tec...alResources/0,,30_182_871_9706,00.html
http://www.amd.com/us-en/Processors/Tec...alResources/0,,30_182_871_9706,00.html