Unassigned an user doesn't remove s/he from the support_assigned table

If one assign someone to a ticket, either from support/ or node/%node/edit, that account is added to the support_assigned table, and appears in the subscribed list. Change the assigned account doesn't remove the previous one, although the status would say "Unassigned >
".

This could be an issue then notifications are sent. It sends to all accounts that have been assigned to that particular ticket.