Probably the problem is that you are considered a New Seller, since you have not sold in a year or so.
There have been many changes.
At this point, for example, your customers' payments will be Held by Paypal for 21 days pending your good behaviour. Nothing personal, this is a Buyer Protection against fly by night sellers.
You may not be able to sell internationally until you have at least 10 recent sales.
http://pages.ebay.ca/help/sell/questions/sell_international_requirements.html
When you can sell internationally (USA doesnt seem to count as international) you will see on Page Three under Shipping Details International Shipping appear. Then you can choose Custom Locations/ Calculated or Fixed Price/ etc.
