Error: Ignoring request from unknown client IP:32772

Hi, I am new to chillispot and freeradius. My setup is as follows. I am using linksys wrt54gl which connects to a server running chillispot which did connect to a linksys router and everything worked fine. I am switching to a new network and I replaced the linksys router with a cisco 1841 router. Also changed the IP address of the cisco router. Changed the IP in the clients.conf. I can register as a user but when trying to connect to the internet, I get the error ignoring request form unkown client IP:32772. Is there anything I need to change, now that I am using a cisco router? Thanks, jon