I see you are trying to compile Perl 5.14.0 - is there any particular reason why you are not compiling 5.14.1, which might already fix your issue?

Other than that, I would still look at the output of ./Configure and check whether (or why) it detects that you have IPv6 socket support. If it correctly claims that you don't have it, this would be a "simple" error in Socket.xs. If it incorrectly claims that you have IPv6 support, it's a matter of fixing Configure, or of moving the code that "works" for Configure to also work in real life.