Pairing Sixaxis driving me insane..

[miseryguts]

Just can't get this to work no matter what I try & have no idea where I'm going wrong (yes I have been very careful following the instructions)
I've used the Sixaxis pair tool & entered the code it gave on the Sixaxis Controller app on my Nexus 7, thing is after I've entered the code it changes to a completely different code to the one I've entered no matter how many times I change it, I've even deleted the app & re-installed.. and it STILL reverts to a different pair code.. WTF!
Anyone got any ideas what on earth is going on here..?

Thanks.