Try to change settings as below. Mode: 11bg mixed Transmit Power: Middle Disable UPnP If they won't help, submit a ticket to TP-LINK support team. http://ticket.tp-link.com/index.php?/Tickets/Submit

WR1042ND has no feature to disable NAT. WR1043ND V2 has the feature. Why you don't use WR1042ND as an access point instead of a wireless router?

Here it is. http://ticket.tp-link.com/index.php?/Tickets/Submit

You keep the router on all the time except that it goes to sleep after 2-3 days and you'll restart it? When I don't need to access internet during night, I'll power off the router and let it have a...

What's the model number? What kinds of connections are you trying to create between clients and router?

How about status of Ethernet light on PA411? Can you access internet by powerline devices? Uninstall the utility. Try to install the newest utility here to see if they can be detected....