Re-reading the first reply from Asus. Appears that they have identified the issue with the firmware as being the modem is acting as a router so they ask you to turn off the router feature. Not familiar with how a DSL or cable modem handles this - live to far in the sticks to have that type of service. I believe your theory maybe correct and Asus has not figured out how to manage the issue with the firmware.
Thanks for the tip on the USB features - more of a curiosity than a need.
Was successful with the old firmware doing backups with the Seagate drive. Most likely will do backups with external drives attached to each computer.