Old Posts Displaying on Homepage

I would like help controlling the number of posts displaying on the homepage of my blog: unfoldingleadership.com/blog. On the Reading setting in wp-admin, I can change the number of recent posts to be displayed, but this does not affect the fact that immediately following them will be all my other posts, beginning in February 2009 — and they will be in ascending rather than descending order (the reverse of the few few posts). You will see on my blog now that the fifth post down is from August, 2010 while the sixth is from February 2009, and the posts following all succeed that, returning toward the bottom of the page to August 2010. Changing templates does not seem to influence this problem. The old posts continue to display in whatever template I choose. I can change where the “break” occurs depending on the number of recent posts to be displayed that I select in the Reading setting.

In the template I am currently using this is not much of a problem, as I can just as easily display many or all of the posts and it won’t affect the look of the blog. But I am hoping to move to a different template where, unfortunately, this problem would be very obvious.

Does anyone know what’s causing this problem and how I might fix it?