There are a few websites I visit regularly who just don't work with IPv6.
www.infowars.com, 2001:4870:6003:3::10 is one.
traceroute shows
7 10gigabitethernet1-2.core1.nyc1.he.net (2001:470:0:37::2) 130.039 ms 125.361 ms 125.455 ms
8 2001:504:1::a500:4323:1 (2001:504:1::a500:4323:1) 124.712 ms 125.326 ms 125.948 ms
9 2001:506:8:0:168:215:52:36 (2001:506:8:0:168:215:52:36) 171.622 ms 168.109 ms 169.165 ms
10 * * *
2001:4870::/31 = tw telecom
Where are tunnel users supposed to report broken routes like this?
It appears broken somewhere in TW. I'll look for someone over there to poke. If you can, you can also try to get the TW customer to ask about it. That's usually the quickest way to get resolution.