This article applies to:
|Google Checkout Fails if all Items have Free Shipping
Customers attempt to pay with Google Checkout and are redirected to the site's home page. The Integration tab in the Google Checkout account shows repeated "Duplicate shipping name Free Shipping found" errors.
This is caused by having "All items have free shipping" set (under Shipping->Shipping Rates Table) and also having each product set to "Is Free Shipping".
Store admins should just set all shipping to free through the Shipping method, rather than in both places.
If all products are already set to free shipping and need to be properly set in bulk, run the following SQL query against your DB (make sure you have a good backup first just in case):
UPDATE dbo.ProductVariant SET FreeShipping=0