I started an almost identical thread on 19th Jan.
I have a network with an XP and a Windows 7 32 bit pc working fine. I added a new windows 7 64 bit pc to the network in November and everything was fine until 17th Jan when I had problems. Thought it was the Linkstation at first then decided it must be the pc so reinstalled windows and have at least now got access to the share folder but NAS Navigator does not wake the drive.
PC has become unstable and keeps re-booting with not even a BSOD so am currently running without NAS Navigator at all to see if that helps.
I have scanned using all sorts of utilities and can find no virus or malware.
Did Microsoft release a Windows 7 update which has afected things? If its exclusive to the 64 bit version of windows perhaps we need Buffalo to review 64 bit compatibility?