I have upgraded to the latest beta firmware for the dir-412 Because I have the Nokia CS-18.
It works! ...The first time. When I unplug the DIR-412 or the CS-18, and restart or re-insert, the CS-18 will not power up.
I reloaded the firmware while it was all together, and it works again! Unplug, same result.
I tried switching to back and forth 3G to WAN. It works, but why do I have to do this?