The issue seems to be linked to OpenDNS.
I do not subscribed to OpenDNS Service, but I use their two DNS IP Addresses.
I consulted with another Admin and he had the same issue with OpenDNS.
According to his experience with OpenDNS, after about 30 minutes his network loses the ability to browse the Internet (WAN) but is able to browse the Intranet (Local).
I tired installing the OpenDNS fix and the router crashed.
I re-built the router and restored the config file.
I removed OpenDNS IP Addresses and is again using the local ISP DNS Service.
I will report the results, good or bad.