|but in the directions on the DVR, in all CAPITAL letters informs you that the DVR will not work behind a 2nd router|
My method would still work as the DVR and the new wireless router would both plug into LAN ports on the old router. Here's how I see it:
Internet >> Old Router >> clients/DVR/new Wifi Router
Just remember, you don't want DHCP enabled on both routers. I would leave the old router (the one connected to the internet) doing DHCP and I would disable it on the new one.
If your old router's LAN IP is: 192.168.0.1 then give your new one: 192.168.0.2 and make it's Default Gateway IP: 192.168.0.1 as well as DNS. You would use the same subnet mask on both.
One last thing, if your old router doesn't have enough LAN ports for everything you need to plug into it, you could move any client other than the DVR to the LAN ports on the new router.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.