With the latest release of Soapbox, we've added in safeguards that prevent duplicate records from being created in Soapbox and Salesforce for the same subsequent payment on a recurring donation subscription. Previously, situations might arise where a payment processor would send multiple notifications to Soapbox that a given recurring donation had been charged for the month. We've both optimized that notification process to prevent the likelihood of that occurring and setup a check to disregard any duplicate notification if it does happen - all to make your Soapbox and Salesforce donation data healthier and happier.
Happy Soapboxing!