Here at our office we're using a cisco 1841 with both a SDSL connection as an ADSL connection. This is all working great actually, the ADSL connection provides our LAN the internet and the SDSL connection is completely seperate and hosts our webserver with it's own IP (so no LAN configured for that connection). Obviously, the ADSL connection has NAT enabled and the SDSL connection is completely NAT disabled. Our problem was like this: At our LAN we couln't connect to our website (so basically we couldn't connect to the IP-range of the SDSL connection). Now we discovered where the problem lies. In the cisco router there are 2 ACL rules defined: Rule #150 has 2 subrules which are
1) Permit, source=any, destination=IP range from SDSL connection.
2) Permit, source=IP range from SDSL connection, destination=any
Now, when we delete the second rule we can connect from our LAN to the SDSL IP's but the rest of the world can't connect to it anymore. When we have both this rules enabled, the rest of the world can connect to the SDSL IP's but we can't connect from our LAN. Also i should mention that when we look with tcpdump we see packages arriving at the SDSL IP's and the replies are there as well, but the route back to the LAN seems to be disabled. There is no firewall installed whatsoever btw. Please give us any information you can think of, because we are totally stunned of how this can happen.
I agree with Peter that your problem is that the Policy Based Routing that is configured is matching responses which should go back to your LAN and sending them out the dialer interface. I would suggest that you need to modify access-list 150 to deny traffic to your LAN before you permit other traffic. I would suggest that you paste this into your router:
no access-list 150
access-list 150 remark SDM_ACL Category=1
access-list 150 deny ip 192.168.0.0 0.0.0.255 18.104.22.168 0.0.0.15
access-list 150 deny ip 22.214.171.124 0.0.0.15 192.168.0.0 0.0.0.255
access-list 150 permit ip any 126.96.36.199 0.0.0.15
access-list 150 permit ip 188.8.131.52 0.0.0.15 any
Give this a try and let us know if it fixes your problem.