Same problem here !
I have 2x
Rev. B1
Fw 1.0
2 Tb disk
Using Windows Server 2008 and Windows 7
On windows server 2008, using ftp, slows down but no errors , using smb, slows down and write protection errors
On windows 7 using smb, slows down, no write protection errors, same using ftp
I also have a Rev. A1 with Fw. 2.02 and 2Tb disk, no problems at all !
Maybe a Hardware rev and/or Fw problems ?