Hi A.J.,
Welcome to Auctiva! There is actually no aspect of our service that would cause the Paypal email address associated with your listings to change. The desired Paypal payment address is actually specified in the "Paypal Notification Will Go To" field when your listings are created.
If you have any active listings for which a now invalid email address was entered in the "Paypal Notification Will Go To" field, and you cannot accept payments at that address any longer, I recommend updating the content of the "Paypal Notifcation Will Go To" field in those listings using eBay's "Revise your Item" form.
Any additional questions or concerns? Please file a support request using the appropriate link on our help page:
http://www.auctiva.com/free-auction-software-help/help.aspx-Mike
