Thank you - i solved the problem above. New problem now - may not be related to Airport Extreme directly... When copying files the operation seems to time out.
To be clear, i have 3 HDs.
A) First is a Western Digital connected to Airport Extreme via USB port - no problems,
B) Second is a Lacie 2Big Network (2Tb) connected to Airport Extreme via Ethernet port, this HD has 2 USB expansion ports, and
C) third HD is a Lacie Rugged 1Tb HD connected to 2Big Network via one of the USB expansion ports.
When i try copying data from C to B the error message i get is: "Error copying file or folder - Cannot copy [insert file name]: The specified network name is no longer available".
I could connect C to Airport Extreme via USB by adding a splitter but what i have should also work, no? Just trying to understand what might be going on.
Thanks for patience,