I would suggest that you need to have all devices on one sub-net.
I've had good success using an additional router as an Ethernet switch and WiFi access point by setting the Actiontec's Dynamic IP range to something like 192.168.1.10 through 192.168.1.254. I then assign a static IP address to the D-Link/Netgear etc. router to a value below the DNS range, say 192.168.1.2.
I turn off the DNS server on the additional device, connect any LAN port on the Actiontec to any LAN port on the second router via Ethernet, and that's it. All devices other devices are assigned an IP by the Actiontec's DNS, and since they're all on the same subset, they all work.
One other thought....there is some disagreement about this on various forums but I've had best success by setting two WiFi access points to different SSIDs on different channels. The radio guy in my finds that works better than having multiple access points on the same SSID and/or channel.
Good luck.