Allow the People tags 'Unknown' and 'Unconfirmed' and 'Ignored' to be used as filter items. They are there in the filter but checking them currently has no effect. Also, they also do not show any qty numbers beside them except '0' As a workaround, I have tagged all 'Unknown' faces as 'Faces-Unknown' so that I can view an album in album-view and then invoke the filter. But this adds an extra tag and also needs manual updating every time a face is ignored or confirmed. Thank you!
*** This bug has been marked as a duplicate of bug 426178 ***