Often times when I open fluent reader (on debian based linux install) I look to the toolbar on the left. This is supposed to show me the number of unread articles I have in each folder. This count is often inaccurate. I will see categories seem read while having unread articles. When I read these articles in the course of using the app the count will go into negatives. The only way to get the count back to zero after it goes into negatives is to manually "mark all as read".