Connecting A Thomson Speedtouch ST585 Router To A Network (dd-wrt)?

I have a thomson speedtouch ST585 router hooked up to my DSL line. I am trying to replace the wifi AP of the thomson with my linksys router (running dd-wrt). So far I have connected the linksys router (from the internet port) to the thomson router, and turned the thomson's wifi off. But, now I can't connect to the internet though the linksys router...I have tried disabling DHCP with no success?

Update:I can now connect to the internet through the linksys router, the problem now is that I cannot access the linksys's routers setup page. I can access the speedtouch's though.[URL] I would like to be able to manage all the forwarding (and the ip's) though the linksys router NOT the thomson (I want to make the linksys router the core router). I just need the thomson for my DSL line, I don't want it to do anything else but provide internet to the linksys router.