I have just bought a 1TB eSATA HDD to use with my N3200. Like you I've formatted it from the Thecus web interface, and I have succesfully mapped a drive to it from my PC by using the path
Hope that helps?
What I can't understand is why this path is still useable even when the eSATA drive is not connected. Can anyone explain? Does the N3200 keep a synchronised copy of the data in the RAID array too or something similar?