I am having a similar issue and would appreciate some advice. For a while, Windows 7 worked just fine with the DNS-321. Lately, however, even when mapping using easy search, transfers fail after about 8gb. I am transferring large files (30 gb) of Bluray material that I have want to transfer from my discs to the DNS321 for archival purposes.
I seems like the DNS321 is somehow not responding to network requests. Any ideas on how to keep it "alive"?