Last week we upgraded our store to Magento 1.1.2. Since the upgrade we are now seeing duplicate orders appear for every order paid via PayPal Express. The duplicate orders have the same order number, but sometimes differing names/addresses.
Both duplicates are posted within 30 seconds to 1 minute or so of each other. It appears to be an issue where the order is getting placed within Magento twice - once before the handoff to the Paypal site, and once again upon the visitor’s return to Magento from Paypal. This was not happening prior to the upgrade, and it only happens with Paypal Express orders - Authorize.net orders are fine.
The Paypal Express payment module Action is set to ‘Sale’.
Has anyone seen behavior like this? I’m interested in discovering whether this is a bug with the payment module code, or something unique to our installation somehow.