This is an old problem that recurs. Some time ago there was a bugfix for this - in glibc.
http://jpmens.net/2011/09/28/aaaa-and-a/ https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/80571
Apparently the patch was not applied in this release (Ubuntu 12.04 LTS Server amd64).
This is an old problem that recurs.
Some time ago there was a bugfix for this - in glibc.
http:// jpmens. net/2011/ 09/28/aaaa- and-a/ /bugs.launchpad .net/ubuntu/ +source/ glibc/+ bug/80571
https:/
Apparently the patch was not applied in this release (Ubuntu 12.04 LTS Server amd64).