Weird Connectivity Problems

I have a CG3000DCR gateway and a /29 block of IP addresses. I have several pieces of equipment that require static IPs including two routers.  Assigning my routers two different IPs in my block and assigning the correct gateway, I am able to ping  and connect to the router from the outside WAN. I can also conncet using OpenVPN and that works just fine. However, running ping tests and trying to browse the web behind the router results in some weird symptoms. First, I do have DNS servers set in the router configuration. I have tried the comcast dns (75.75.75.75, 75.75.76.76) and google dns and opendns. They all resolve just fine. However, I can't browse behind the router. I need some help. This almost sounds like a problem on Comcast's end and not mine.