I'm not sure what the bug is but I ran into a similar problem recently as the seller. I had temporarily stopped internatial sales because of the new VAT taxes for Europe. In my case which countries I ship to is set up in my "SHIPPING POLICIES". I have one Policy for Canada and US only and another that includes International. This way I can use the appropriate shipping policy if someone has contacted me and I wish to let them buy.
This only works if there are no bids on the item - you can't adjust the shipping policies on items already bid on.
Perhaps she only has one policy she is using for all her listings and if any have active bids it can't be changed.
Because this happened to me I set up a new policy for just such cases.
Not sure if it will help but it worked for me! Good luck!