Carbon-14 testing isn't very reliable if you ask me. I've never thought the shroud to be authentic.
I was in Torino last year and went to the church where it is stored. Although you can only see pictures and copies and other memorabilia now, they have done a great job in the presentation, including a computer model of what the person in the shroud looked like.
Needless to say, I was quite moved and thought it was authentic despite the evidence from the Carbon dating test (which may now be questionsable).
I would encourage you to go and see for yourself....
It is, actually, when used on suitable samples. Unfortunately, a favorite trick of young-earth creationists is to use it on samples known to be inappropriate for 14C testing, and then use the (not surprisingly) invalid results as "proof" that radiocarbon dating is "inaccurate".