Am I being stupid?

[Dirk Koopman]

Last week I upgraded a linux server from 10.04 -> 12.04. A program that 
has been running happily bound to an ipv6 address and successfully 
accepting callers has stopped working. I have tried using my "official" 
ipv6 address of 2a00:9080:1:5cf::1 and also the link address (as below). 
They both give the same error.

bind: Invalid argument at /spider/perl/Msg.pm line 319.
  at /usr/local/lib/perl/5.14.2/AnyEvent/Socket.pm line 1180.
	AnyEvent::Socket::tcp_server('fe80::beae:c5ff:fe4d:8cb9', 7300, 
'CODE(0x943c22c)') called at /spider/perl/Msg.pm line 319
	Msg::new_server('ExtMsg', 'fe80::beae:c5ff:fe4d:8cb9', 7300, 
'CODE(0x940ecf0)') called at cluster.pl line 472

Has something changed, or was I doing it wrong in the first place?

Dirk