For a while, DeskPRO's logic for the Unassigned tickets listed below was to included tickets that were not assigned to a specific agent.
Whether a ticket was assigned to a team or not, had no affect on whether the ticket was listed as Unassigned.
As per 20th March 2014, this functionality has changed. An unassigned ticket is a ticket that is neither assigned to an Agent or an Agent Team.
We believe this change helps those companies that use the team structure extensively. Tickets can be assigned to an agent, a team, both or to nothing. Only "nothing" would now make the ticket unassigned.
If you want to be able to find tickets that are assigned to a team, but not an agent you can create a custom filter.