This is an overview of my IP Cache Statistics:
security.debian.org 2001:a78:5:0:216:35ff:fe7f:be4f-OK
2001:a78:5:1:216:35ff:fe7f:6ceb-OK
2001:8d8:2:1:6564:a62:0:2-OK
212.211.132.32-OK
212.211.132.250-OK
195.20.242.89-OK
bugs.debian.org 2001:858:2:2:214:22ff:fe11:ac9e-OK
86.59.118.149-OK
140.211.15.34-OK
sixy.ch 2a02:200:3:1::103-OK
80.254.71.229-OK
www.sixxs.net 2001:1af8:1:f006::6-OK
2001:838:2:1::30:67-OK
2001:960:800::2-OK
213.197.30.67-OK
213.204.193.2-OK
94.75.219.73-OK
www.ripe.net 2001:610:240:22::c100:68b-OK
193.0.6.139-OK
In my case connections to bugs.debian.org, sixy.ch and www.ripe.net work.
The others dont.
It seems to me, if host with more than one AAAA record do not work.
But i cant proof it.

