I have EOIP working with my buffalo routers, I have 3 of them connected. Your link to the wiki is not working but that is the same guide I used.
Once you are configured, reboot the routers and then log on to one and click the status tab, then the lan tab. You will want to look at the active clients list. If they are connected then you should see the unique ip address that you assigned in the eoip configuration page.
Router 1 Setup: Private Local IP - 192.168.1.1
Tunnel 1 - Remote Site#1
EoIP Tunnel - Enable
Remote IP Address - Public IP of remote router 2
Bridging - Disable
IP Address - 192.168.202.3
Subnet Mask - 255.255.255.0
Router 2 Setup: Private Local IP - 192.168.2.1
Tunnel 1
EoIP Tunnel - Enable
Remote IP Address - Public IP of remote router 1
Bridging - Disable
IP Address - 192.168.202.2
Subnet Mask - 255.255.255.0
Now Click on the Advanced Routing TAB and set the routing for each of the tunnels.
Router 1: Advanced Routing Tab:
Select set number
1 ()
Router Name: (Give it a unique name Site1)
Destination LAN NET - 192.168.1.0 <--Note the routers local ip is set to 192.168.1.1, set this to 192.168.1.0 here
Subnet Mask - 255.255.255.0
Gateway - 192.168.202.2 <---This should match the settings on remote router 2 settings in the eoip tab
Click save and then apply. Then click on show routing table.
You should see this on router 1 in the routing table.
192.168.2.0 255.255.255.0 192.168.202.2 UG 0 oet1
192.168.202.0 255.255.255.0 0.0.0.0 U 0 oet1
Router 2: Advanced Routing Tab:
Select set number
1 ()
Router Name: (Give it a unique name Site2)
Destination LAN NET - 192.168.2.0 <--Note the routers local ip is set to 192.168.2.1, set this to 192.168.2.0 here
Subnet Mask - 255.255.255.0
Gateway - 192.168.202.3 <---This should match the settings on remote router 1 settings in the eoip tab
Click save and then apply. Then click on show routing table.
You should see this on router 2 in the routing table.
192.168.1.0 255.255.255.0 192.168.202.3 UG 0 oet1
192.168.202.0 255.255.255.0 0.0.0.0 U 0 oet1
Make sure each router is not using the same private Local IP.
Looking over your configuration doc nothing jumps out at me except the firmware versions. I have tested only the beta firmwares. All of the ones released in 2013 have worked for me.
Check the active lan clients list and see if they are showing up there. This can be found in the status tab,