If you set a static IP address, that may be your problem.  I think Arris modem/routers use 10.x.x.x ips.  But most home routers use 192.168.x.x  So, if the miner is set to a 192.168.x.x address, that may be your issue.  Follow the instructions under 4) configuration here https://bitcointalk.org/index.php?topic=702653.0 to get it working.