new iPad Air won't turn on after restoring iPhone 4S backup to it

This one is probably a bit weird or specific so hopefully someone from Apple can support me with it.

I have an iPhone 4S that is just over 2 years old which I bought in the UK. I have now emigrated to Australia and have just bought a brand new iPad Air here. Although the charger adapter that came in the box isn't an Australian plug as the 2 pins are straight up and down rather than at a 45 degree angle. That may or may not make any difference.

Last week I updated my iPhone to iOS 8.02. After I had set the iPad up as a new device, the first thing I did with the iPad was plug it into the macbook and update it to iOS 8.02 through iTunes.

I want my iPad to look just like my iPhone, same apps, same folders, same settings, same contacts and mail accounts etc. I did this for my wife's iPhone and iPad about 7-9 months ago in the UK both UK devices and it all worked fine on the software at the time.

I have changed the location on my iTunes account to be Australian and changed all my contact details to be my new details.

When I restore the latest iPhone back up my iPad the iPad won't turn on any more. It also won't reboot with a long press of the power button, but when I connect it up to iTunes it is recognised. It also initially says it is only a 16GB iPad, but I have a 32GB iPad and a 16GB iPhone 4S. When I try and do anything in iTunes like sync or backup or apply changes it says I need to input my security key, but I can't on the iPad because the screen won't light up.

If I restore the iPad to factory from iTunes then the screen works again and it's all OK. So I then tried doing a brand new iPhone 4S backup which I encrypted to ensure that all passwords where backed up and tried restoring that backup to the iPad, but it had the same issue.

Is this an iOS 8.02 specific defect or something to do with trying to restore a UK iPhone to an Australian (or other country) iPad?

Please help.