Buyer address glitch

Good morning,

 

I have a buyer with a weird glitch.

She is in Australia, but when she goes to pay, it says I "will not post to her address".

She's getting frustrated because she can't pay for the item.

Between her and myself we can't figure out why she is getting the error.

Her address is not a PO Box, but that wouldn't matter as I post to them anyway.

 

Any ideas?

 

Thanks