@limetech Thank you for the explanation that, makes total sense now.
I have just tried using an MBR partition as suggested by a few people and that does work. I would prefer to use GPT though. I'm sure it makes little difference but its one of those GPT is the new hotness type of things, if that makes sense .
Would defiantly be good if you can add that in the next release, I kind of thought that was the whole point of having to label it UNRAID so you could search for and find the correct volume :D.