How does "Slashdot style" decide what to highlight on the home page?

Need to understand how the Slashdot homepage style works because it's not doing what I expected

I'm using a slight customization on the skeleton skin, with the home page display set to Slashdot style. I have the "Display __ articles at the home page" setting at 7.

I posted 2 new articles and updated several more...I expected both of the new articles to show summaries at the top of the home page, but only one does.

What is the slashdot algorithm for deciding what to display up front, or how to a get that second article to show with the other new posting?

Site is at www.morison.biz/technotes. The new article that does show is http://morison.biz/technotes/articles/view.php/15. the article that doesn't show on home is http://morison.biz/technotes/articles/view.php/16.

Any help or pointers are appreciated.

Thanks,

Rod

PS: I just noticed that the new article didn't show up in the RSS feed for new articles.