Do not go thru the router , run a tracert to google.com and see if it shows IPv4 or IPv6 addresses.
If it shows IPv6, you have the router set wrong. I assume you have the 862 in bridged mode....
If you're using an external router with wireless, the 862's wireless radio must be off as well as be in bridged mode.
Do you pay for TWC phone service? There are cases where TWC phone and IPv6 are not useable in the same modem
What's your zip, maybe some user here is in that area, I'm up by Cleveland and don't need IPv6 and am waiting until TWC get's it fully implemented. I have a 6141 without any phone service and it appears to be fully IPv6 capable thru a win 7 direct connected laptop