One of my customer has same type of issue couple of years back and below was the solution,
configure vlan bedvu212 router-discovery ipv6 add dnssl sumittokle.com
configure vlan bedvu212 router-discovery ipv6 add rdnss 2620:f6:8000:3::2
configure vlan bedvu212 router-discovery ipv6 add prefix 2620:f6:8000:2711::/64
configure vlan bedvu212 router-discovery ipv6 set prefix 2620:f6:8000:2711::/64 autonomous-flag on
configure vlan bedvu212 router-discovery ipv6 set prefix 2620:f6:8000:2711::/64 onlink-flag on
configure vlan bedvu212 router-discovery ipv6 set prefix 2620:f6:8000:2711::/64 preferred-lifetime 604800
configure vlan bedvu212 router-discovery ipv6 set prefix 2620:f6:8000:2711::/64 valid-lifetime 2592000
configure vlan bedvu212 router-discovery ipv6 min-interval 30
configure vlan bedvu212 router-discovery ipv6 managed-config-flag on
configure vlan bedvu212 router-discovery ipv6 other-config-flag on
enable router-discovery ipv6 vlan bedvu212
enable router-discovery ipv6 vlan cc3uc1
http://en.wikipedia.org/wiki/Comparison_of_IPv6_support_in_operating_systems
Windows does not support rdnss without a special addon.
I see from the advert that the switch is sending the dnssl and rdnss. Tests on linux/mac that support this grab the dns list fine.