A faculty member called asking why his blog was only showing one post, even though he had set it to show 7 posts at a time. I verified the setting, had no clue, and googled it to find this page which said [essentially] that dragging and dropping images can cause this problem. How random is that! I asked the professor if he had dragged and dropped images and, yes, he did so he removed the post and redid it by inserting the image and it went back to showing 7 posts per page.
Unfortunately Blogger then began misbehaving in other weird ways, so he moved from Firefox to Internet Explorer which resolved that issue but called again later to know why he couldn't get text to wrap around the new images like it had before, which required moving back to Firefox. Oh Blogger!