Comment 8 for bug 137409

> I've seen 3 and 4, too. But this is only "visual", i.e. if you switch to another feed and back, all should be fine again, right?
That is correct.

> It's not about dupe detection, it has to do with the list items (which are created per article).
Thanks -- sounds very logical. The reason I suspected "dupe detection" originally was that it only happens with new (red) and unread (blue) items. The read items (black) items does not seem to be affected.

> Thus, when switching to another feed and back, the items are cleared and recreated properly.
Yes. That is also correct.