You might notice that editing a child-level event registration in a multi-level event, the registration tab does not update correctly when a registration is deleted from the edit registration form.
We are currently evaluating this issue for a fix in a future service pack.
Steps to Duplicate
1. Create a multi-level event with 3 child-level events. 2. Add the same registrants to each child-level event. 3. Go to the Registration tab of one of the child-level events 4. Edit the registration of one of the registrants. 5. Delete the registration one of the child-level events and click save. 6. Notice that the registrant still appears to be attending all child-level events.