Thanh,
I mentioned this before, and I understand that it may not be ideal, but you can still try setting up the OBi using the phone method. It's not even certain that it will work. This would be your Plan B. Pick an IP outside the router DHCP range. I have read on the forum several people using a static IP with the OBi. If it works, you will not need to swap routers and you can start enjoying the OBi within the next 10 minutes. Your other choices seem clear enough, change router, return the unit, or spend more time trying to figure out the router issue. Let us know what you decide. Good luck.