Also - It would be HUGE to be able to assign staff to production statuses so they get an email of what needs to be done. I.E: If print films is the next status, our artist will get an email when it changes over to "Needs Films". This will also allow you to create a simple "Tasks" panel which shows each user what needs to be done for the day.
So the filter widget was only intended / coded to have 1 instance on within a page.
I can see somehow its allowed you to add multiple instances.. and I can see why you have done it that way for flexibility.
I will pass back to my developer to see if he can get running with multiple instances on 1 page. In the meantime if you were to only have 1 instance added with multiple options ticked it should behave correctly.