When using an eCard Part and accepting donations, if you get to the confirmation screen and hit the Screen Refresh button or CTRL F5 to do a screen refresh, this may create another transaction and charge the card again without entering new form data.
This is resolved in the latest version of NetCommunity.
Steps to Duplicate
Fill out eCard form
Enter donation information
Hit the refresh page button
Notice you get another confirmation email and you will notice in BBPS a new authorization number is created for new transaction