For the last week or so of Thunderbird 2.0 nightlies, hitting "n" to take me to the next unread message after I finished reading all NNTP messages often takes me back through the NNTP messages I've already read. The messages get correctly marked read the first time I read them (they get unbolded and the newsgroup's message count goes down), but "n" brings me back through them anyway, and hitting "n" repeatedly walks me through the messages. But it only walks me through the messages one additional time. Once I arrive at the last message I read the first time around, hitting "n" no longer does anything (unless a new message has arrived in the meantime, in which case it correctly takes me to that message). I'm not sure yet how often this happens or what factors may prompt it to occur, but I've seen in numerous times this last week, so here's the bug. I'll pay attention to it and comment further once I know more.

*** This bug has been marked as a duplicate of 363966 ***