Two readers of this site have reported a glitch where they read the posts on the first page and then when they get to the bottom and click "Older Posts," it takes them back a week. This is not a problem I can fix, especially since it doesn't happen on any of my three computers or my iPad or my iPhone. It may be a bug in WordPress, the software that drives this site. If it is, they'll probably get around to fixing it but there's nothing I can do.
Here's a tip if you're having that problem. You can read posts here by the page or by the post. To go into one-post-to-a-screen-mode, just click on the Subject of any post and you'll go to that post and only that post with links at the bottom so you can read forward or backward. That should avoid the jumping problem and sooner or later, it will go away for you. Sorry.