Hi John,
I'm using Joomla 2.5.1 and VM 2.0.1.f. Here's the details: With one product in the cart in US $, I press the Confirm Order button to check out, it goes to PayPal, but then PayPal immediately gives this message: Unable to process payment. Please contact the merchant as the shipping address provided by the merchant is invalid, and the merchant has requested that your order must be shipped to that address.
This exact product works fine start to finish with Joomla 2.5.1 and VM2.0.0. Something changed between VM 2.0.0 and 2.0.1.
I do not have any shopper groups set for the products. As an experiment since you mentioned shopper groups, I tried setting the shopper group for one product to -default- and then -anonymous-, but it gets the same PayPal error for both groups.