Cannot keep two xbox's connected

[Dinggus]

I have a Netgear WGR614V9 router, my room mate and I are trying to play BlackOps 2 on both our xbox's via WiFi. We can connect to the same game, but within like 5 minutes, we get the "connection lost" icon, and then one of us or both are disconnected from XBL. It's weird because we can play MW3 or Halo 4, but Black Ops 2 won't let us.

From googling, there are MANY different ways to make this work, but I figured I'd ask Neowinian's before wasting time or/and money. People recommend Power Line (plug in network adapters), turning off router security, open NAT's (I have no clue how or what that is), router isn't XBL compatible, xbox's are automatically assigning same IP, etc.