I am not sure how this setup works, but I am assuming the harddrive gets assigned and IP address like it is a computer connected to the router? If so, how do your machines resolve the netbios name of the drive? I guess I am asking when the drive is on your router, and you access it from your PC, does it appear as another computer?
That said, how do you make a share point on the drive that way? When you connect via network share the hub asks you if it is Windows or Linux, and the remote drive has to be announcing that it is available, and then that it has share points to connect to.
Sorry no answer, just more questions, but it is an interesting setup.