When registering for an event using the Event Registration Form 2.0 in BBIS, blank values from the form can overwrite existing constituent address information for the matched constituent.
We are currently evaluating this issue for a fix in a future service pack.
Steps to Duplicate
1) Register for an event in BBIS using the new Event Registration Form, leaving the address fields. 2) Download the transaction into CRM. 3) Make sure the constituent is auto-matched, then validate and commit the batch. 4) Notice that a blank address is now the matched constituent's primary address.