If i understand correctly, you have a wireless ADSL modem/router with DHCP enabled and set as a AP with WEP. Your second router must be set to client mode.
1.) The gateway router(The adsl router) must be left to pppoe and the client router must have a IP
" Set Wireless Setup.Internet IP Address = 192.168.1.2 (or whatever ip address you identified in step 2 of preperation)
Set Wireless Setup.Subnet Mask = 255.255.255.0 (same as assumption #3)
Set Wireless Setup.Gateway = 192.168.1.1 (Same as assumption #2)
Set Wireless Setup.Static DNS 1 = 192.168.1.1 (Same as assumption #2)
Set Wireless Setup.Static DNS 2 = aaa.bbb.ccc.ddd (Same as assumption #4)
Set Wireless Setup.Static DNS 3 = aaa.bbb.ccc.eee (Same as assumption #5)
Set Wireless Setup.Router Name = BRIDGE (doesn't matter what you name it)
Set Wireless Setup.Host Name = BRIDGE (doesn't matter what you name it)
Set Wireless Setup.Domain Name = Blank (unless you have a reason to enter it)
Set Wireless Setup.MTU = Auto
Set Network Setup.Local IP Address = 192.168.2.2 (increment the 3rd octet of the Wireless Setup.Internet IP Address field by 1, e.g 192.168.1+1.2. So now 192.168.1.2 is your ROUTER facing IP and 192.168.2.2 is your CLIENT network facing IP.
Set Network Setup.Subnet Mask = 255.255.255.0 (Same as assumption #3)
Set Network Setup.Gateway = 192.168.2.2 (Same as #13 above)
Set Network Setup.Local DNS = 192.168.1.1 (Same as #6 above)
Set Network Setup.DHCP Server = Enabled (To let the CLIENT issue dynamic IPs to the devices hooked up to it)
Set Network Setup.Starting IP Address = 192.168.2.100 (You may have to click on Save Settings button before you see 192.168.2 written in this field. If you do, make sure you connect back to the CLIENT using the ip address is #13 above)
Set Network Setup.WINS = 0.0.0.0
Click on Save Settings button. Notice that after this configuration, your CLIENT bridge/router has a different IP address for administration. So if you are not automatically redirected to the new IP, you may have to connect to the administration web page by typing 192.168.2.2 yourself. Also note that at this stage, you may not be able to connect to the new IP unless you are using a computer hooked up to one of the LAN ports of the CLIENT itself. And you may need to temporarily setup your computer's TCP/IP config to use a static IP in the 192.168.2.* subnet. "
2.) The modem's IP can stay 192.168.1.1
3.)It should not matter because:
"Devices connected to the Client Mode router will not be able to use the DHCP server from the host router. Also, a device connected to the Client Mode router should use the Client Mode router as it's gateway and DNS server."
Another less confusing way is to switch off DHCP on your client router and give everything fixed IP's, for instance, give the client router an address op 192.168.1.2 and your client pc's that are plugged into the client router an IP of 192.168.1.3/4/5/6/7/8/9 and so on with a default gateway of 192.168.1.1 and your ISP's DNS.
