IP addresses
This is the scenario - I have an Airport and Ethernet network for net access that's been working reliably for many years. The hardware and settings consists of:
Actiontec ADSL router - IP 10.0.0.138, DHCP off
Airport Extreme 802.11g - IP 10.0.1.1 (Internet IP setting in Airport Admin Utility is 10.0.0.1, subnet 255.255.255.0), "share a single IP using DHCP & NAT 10.0.1.1 addressing" on, router address 10.0.0.138
2x Airport Express (for extending the Airport network) - IP 10.0.1.232 & 233
Client computers - IP 10.0.1.2 etc, Router IP setting 10.0.1.1, DNS Servers as provided by ISP
My questions are whether the Actiontec router's IP should actually be 10.0.1.138 and, If so, why has it worked with 10.0.0.138 during all this time?

2.0GHz MacBook, 15" 1.25GHz/12" 1GHz PBs, 2xPPC Mac minis, 12" iBook G4,, Mac OS X (10.4.8), Cube, 2xTAMs, iPod 4G & nano 2G, 1G & 2G iPs, AEBS, AX