“Next Page” and archiving issues in 1.5-beta-1

After upgrading to 1.5-beta-1 2005-01-23, I notice that there was a “Next Page” link at the bottom of my index.php. It seems to link to /page/2, but when I click on it, there’s a 404. What is this, and how do I configure my site so that there isn’t a 404?

Another thing, on my December 2004 archives page, there is also a “Next Page” link at the bottom of the page. When clicking on it, I find a “Sorry no posts found” message. This is disconcerting, because the December archives page stops at my 12/21 entries, when I know for a fact that I have a couple of December entries prior to that, and they weren’t on the December archives page.

Example:
http://neekole.com/archives/2004/12/ – December archives – note that it stops at 12/21.

However, take a look at:
http://neekole.com/archives/2004/12/20
http://neekole.com/archives/2004/12/19
http://neekole.com/archives/2004/12/18

The three links above prove that I do have December entries prior to 12/21, but they were not shown on the December 2004 archives page. What’s up with that?

Hope you can help,

Nicole