It seems that I have the same problem ... isn't really a problem, but I would like to understaind.
I have the internal IP address of the modem which is 10.0.0.138 and the IP address of the WAN port of the m0n0 is 10.0.0.139.
Everithing works perfect except that I can not see the web server of the modem (
http://10.0.0.138 ) trough any PC connected to the 3 networks of the m0n0 ( DMZ, LAN, WIF ). The only way is connect a PC directly to the MODEM port with proper IP configuration and than works.
Thank for anybody answer.