Newsblur's Android app can tend to get buggy - as you're scrolling through items by swiping right-to-left, sometimes it'll end up on a blank item, and the whole feed will be marked as read. It also sometimes shows some count X for a given folder, but will show less than X items.

On the upside, Samuel seems to be very quick to respond to issues, and pushes updates out pretty often, both to the app and to the site.