Role Precedence

Hi

I have 1 role of orig system type WF_local_role with name XYZ and a PER Role with the same name XYZ.. The Local role has a notification preference of QUERY and the PER role has the notification preference of MAILHTML. When i assign the user XYZ to a notification, which role is assigned to the notification. I mean i dont want the emails to be sent hence i have created a Local role with notification preference as QUERY. It used to work earlier and not now. For some reason always it chooses the PER role and workflow notification goes