said by AnonMan :Nope, I have had IPv6 from day one on this modem.
Also I know the local maint techs and area sup and they stated no changes are planed for this CMTS for the next year or 2 so it wont have anything to do with equipment neither.
d3000-v302r125532-121212a-L2VPN-CMCST has some fixes that we requested for IPv6, not on the CPE side but the DOCSIS side.