On my blog I'm having a somewhat strange little issue. If you go to http://lnfalandino.com/category/media/ and click "Previous Entries" several times you'll come to a post titled "New Music Picks". On this page there is another previous entries link, but there shouldn't be one there. If you click it, it takes you to an error page. On the sidebar those category post counts are correct: There are 5 posts in Music, 1 in Books, and each of these 6 posts are also a member of Media.
If you click on the Music category in the sidebar, you'll see that it correctly doesn't display the previous entries link when you reach the oldest post in the category.
This is using the stock, default WP theme. I haven't modified any code that could cause this. Also, I've gone through the post2cat table in the DB and everything looks completely normal there. So, at this point I'm at a loss. It isn't a real problem, I'm just curious why it's happening.
Note: I have tried refreshing my permalink settings, or completely getting rid of them. The behavior is exactly the same regardless of those settings.