Sometimes the Android app refreshes feeds without refreshing stories. I can have unread stories like so:
But choosing all stories only shows more grayed out read items (sometimes with a couple unread items).
If I choose a feed instead of all stories, usually it just shows greyed out read stories.
I am using version 2.0.2 of the app. In addition to the problem described above, I also have slow loading and mark as read problems.
I just noticed that you’re experiencing at least 3 different android bugs that are all believed to be fixed and generally unrelated under the hood - it looks like youre phone is experiencing a more general issue with the app.
What phone model are you using, and which exact operating system are you running? Are you generally connecting over a mobile network or a wi-fi network? Are you running any task killers or battery savers?
I’ve got a Samsung SGH-T959P running Android 2.2.1. I’m generally connecting over a good wifi connection. I am not running any task killers or battery savers.
Oh, and I have tried deleting all the app’s data and reinstalling it.
Ohh, I don’t think Android < 4 is well supported. It works, but that would explain many of the issues.
Ah, in particular, support for Android 2.2 and below are going to be poor, end of story. Unfortunately there isn’t much we can do to work around how bad the 2.2 system is. One really basic example is the network client - it reliably fails at least one in five connection attempts, and there isn’t anything app developers can do to work around the issue without crippling everyone else. 
All I can suggest is that you work with your phone carrier or manufacturer to try and get any update from within the last 3 years.