I was just posting the answer to this - TYVM!
I found another post on the forum about someone wanting to add extra fields..
The answer there was regarding the number of fields in the array need to be the same...
In my case I deleted some elements from both arrays that I do not use in the checkout form... After doing this the value of country in the select menu also gets copied and filled in the select menu for shipping nicely...
SO I guess make sure number of fields in both arrays are the same and delete fieldnames which you don't use from both arrays?!
Did the trick for me...
Still TYVM for you reply...