I Initially posted this in the General Support but didn't realise there was a separate discussion for Addons. Anyway, I wonder if someone can help as this is driving me mad........
I've installed the "UK Royal Mail & Overseas Shipping Methods 21st Aug Prices" (http://addons.oscommerce.com/info/4473) module to enable shipping options for UK and overseas delivery. I have a PayPal Sandbox account so I then created two test buyer accounts, one with a UK postal address and one with a US postal address. I then created 2 customer accounts within osCommerce with the same UK and US addresses. When I carried a test purchase for the UK postal address the checkout correctly displayed delivery options for Royal Mail 1st class, Royal Mail 1st class Recorded, Royal Mail Special Delivery, Royal Mail Standard Parcels and Parcelforce48 - each of the delivery prices were also correctly calculated. However, when I tried a test purchase for the US postal address none of the airmail/international shipping options were displayed. Instead the checkout process simply took me straight to the PayPal Express checkout to pay the amount of the goods without any shipping costs added on.
Any idea what I've done wrong or why the airmail/international shipping options aren't displaying?? Otherwise, what alternative shipping modules are recommended for calculating shipping prices to an overseas postal address - one which not only calculates the shipping cost based on the weight of the product but also adds the cost to the final payment within PayPal Express Checkout?